Member Profile

@article{nokey,

title = {Phase-Stable Palladium Hydride Derived from PdCoO2 for Sustainable Hydrogen Evolution Reaction},

author = {L Camuti and S Kim and F Podjaski and M Vega-Paredes and A M Mingers and T Acart\"{u}rk and U Starke and B V Lotsch and C Scheu and B Gault and S Y Zhang},

url = {\<Go to ISI\>://WOS:001555162600001},

doi = {10.1002/adfm.202514366},

issn = {1616-301X},

year  = {2025},

date = {2025-08-22},

journal = {Advanced Functional Materials},

abstract = {Active and reliable electrocatalysts are fundamental to renewable energy technologies. PdCoO2 is recently recognized as a promising catalyst template for the hydrogen evolution reaction (HER) in acidic media, thanks to the formation of exceptionally active PdHx. In this article, the transformation process of single PdCoO2 particles during HER is monitored and elucidated, confirming their almost complete transformation to PdHx. Using operando mass spectrometry, Co dissolution from the PdCoO2 template is observed under reductive potentials, with a partial current of 0.1% of the HER current, while PdHx is formed simultaneously. High HER activity of this phase is retained with long-term operation, dry storage, or vacuum exposure. Isotope labeling of hydrogen using D2O confirms the formation of a stable PdHx phase by secondary ion mass spectrometry and down to the near-atomic scale by atom probe tomography. A separation between D-poor alpha- and D-rich beta-Pd hydrides is observed with an overall composition of beta-PdD0.64. These findings highlight the critical role of a templated growth method for obtaining stabilized PdHx, enabling Pt-like efficient HER without the commonly slow activation processes observed in Pd due to rate-limiting material hydrogenation. This offer insights into the design of more efficient electrocatalysts for renewable energy technologies.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Structure and Transport Properties in the Pseudobinary Phase System Li4SiS4-Li4SnS4},

author = {L G Balzat and Y Li and S Dums and I Moudrakovski and K Gjorgjevikj and A Schulz and Y H Li and S Krause and P Canepa and B V Lotsch},

url = {\<Go to ISI\>://WOS:001551105400001},

doi = {10.1021/acs.chemmater.5c00358},

issn = {0897-4756},

year  = {2025},

date = {2025-08-15},

journal = {Chemistry of Materials},

abstract = {Thio-lithium superionic conductors (thio-LISICONs) are a family of promising solid electrolyte materials for potential applications in solid-state batteries. The orthorhombic polymorph of the thio-LISICON Li4SiS4 (o-Li4SiS4) has been known for decades, but its complete crystal structure has been reported only recently. Here, using single-crystal X-ray diffraction, we reevaluated the crystal structure of o-Li4SiS4 and showed that o-Li4SiS4 crystallizes in space group Pmn21 (no. 31},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Long Used but Hardly Known: Synthesis and Crystal Structure of Tritium Breeding Li2Be2O3},

author = {G Krach and J Steinadler and R Calaminus and B V Lotsch and W Schnick},

url = {\<Go to ISI\>://WOS:001546654300001},

doi = {10.1002/chem.202502209},

issn = {0947-6539},

year  = {2025},

date = {2025-08-11},

journal = {Chemistry-a European Journal},

abstract = {A main challenge for the operation of a nuclear fusion reactor is the consumption of tritium during the fusion process and the limited availability of tritium in natural resources or its production in nuclear power plants. The most promising approach is breeding of new tritium within the operating fusion reactor. For this purpose, suitable breeding materials are needed. Lithium beryllium oxides are a promising class of compounds, as they unite both target and neutron multiplier in one material. While there have already been studies on sintered ceramics in the Li2OBeO system, the crystal structure of compounds of a defined composition has so far remained unsolved. Herein, we report on the synthesis of phase-pure Li2Be2O3 in a high-temperature (HT) approach and its structure determination by single-crystal X-ray diffraction (sc-XRD). In addition, the compound was characterized by powder X-ray diffraction (PXRD), solid-state nuclear magnetic resonance (NMR) spectroscopy, and elemental analysis. The thermal stability, which is important for use as blanket material in a fusion reactor, was examined with differential scanning calorimetry (DSC).},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Predict before You Precipitate: Learning Templating Effects in Hybrid Antimony and Bismuth Halides},

author = {J Blahusch and K S Jakob and J T Margraf and K Reuter and B V Lotsch},

url = {\<Go to ISI\>://WOS:001522359000001},

doi = {10.1021/acs.chemmater.5c00350},

issn = {0897-4756},

year  = {2025},

date = {2025-07-02},

journal = {Chemistry of Materials},

abstract = {Hybrid organic-inorganic (HOI) antimony and bismuth halides exhibit diverse structural features and have been studied intensely for their promising electronic and optical properties. There are well-explored structure-property relations for these materials. However, a thorough understanding of the synthesis routes and templating effects is lacking, turning their targeted synthesis into an open challenge. In this study, we assemble a literature data set of established HOI material candidates and train an explainable machine learning classification model to explore the templating effects in more detail. With a classification accuracy upward of 70%, our model is effective in predicting HOI structure types based on the reactants and points out several structural and electrostatic design features for the organic cation that influence the inorganic substructure most strongly. We further demonstrate the validity of our classifier on 9 newly synthesized members of this materials class and propose incremental learning routes to expand the model in future research.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Identifying Bottlenecks in the Photocatalytic Oxygen Evolution Reaction with Covalent Organic Frameworks},

author = {S Trenker and H A Vignolo-Gonzalez and A Rodr\'{i}guez-Camargo and L Yao and M A Zwijnenburg and B V Lotsch},

url = {\<Go to ISI\>://WOS:001501845400001},

doi = {10.1021/acs.chemmater.5c00804},

issn = {0897-4756},

year  = {2025},

date = {2025-06-03},

journal = {Chemistry of Materials},

abstract = {Covalent organic frameworks (COFs) have emerged as promising semiconducting materials for photocatalytic applications due to their large surface area, high crystallinity, and vast synthetic tunability. This is especially noticeable in the context of photocatalytic water splitting, where many COFs have been employed for the hydrogen evolution half-reaction. There, sacrificial reagents typically replace the kinetically demanding oxygen evolution half-reaction. On the contrary, only few reports focus on (sacrificial) water oxidation with COF photocatalysts. In most of these cases, cobalt species are employed as oxygen evolution cocatalyst, often with limited insight into their structure and detailed role in the catalysis. Herein, we use heterogenization of a molecularly defined iridium half-sandwich complex onto a bipyridine-based COF (Ir@TAPB-BPY COF) and provide detailed structural insights ensuring the integrity of the targeted cocatalyst. First, we demonstrate the retained catalytic activity of the anchored Cp*Ir(III) motifs in chemical water oxidation experiments. In contrast, subsequent photocatalytic and electrocatalytic tests indicate that Ir@TAPB-BPY COF does not evolve oxygen and that careful control experiments have to be conducted in order to avoid false positive results, caused for example by the sacrificial electron acceptor. Using computational methods, we trace back the missing performance to thermodynamic and kinetic limitations of the employed systems. This work demonstrates the pitfalls associated with low-performing oxygen evolution photocatalysts as well as the indispensability of control experiments and their careful evaluation.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Rediscovery of the Forgotten Middle Child: A Comprehensive Study on the Coordination Chemistry of Melam},

author = {T J Koller and L G Balzat and J Blahusch and A Pichler and B V Lotsch and W Schnick},

url = {https://doi.org/10.1002/ejic.202500240},

doi = {https://doi.org/10.1002/ejic.202500240},

issn = {1434-1948},

year  = {2025},

date = {2025-05-28},

journal = {European Journal of Inorganic Chemistry},

volume = {28},

number = {15},

pages = {e202500240},

abstract = {Melam or bis(4,6-diamino-1,3,5-triazin-2-yl)amine is a chemical compound that has already been studied by Liebig almost 200?years ago. Despite this, melam's ability to act as a bidentate ligand has hardly been explored so far. The main focus of this work was therefore to advance the knowledge about melam's coordination chemistry by the synthesis of its complexes with CuCl, CuBr, CuI, CuCN, and AgCl as well as their structural characterization by single crystal and powder X-ray diffraction. Their crystal structures were found to feature channels along the molecules? stacking direction. It was further shown that these melam complexes have excellent hydrolytic and thermal stability, making them potentially interesting for heterogeneous catalysis in aqueous media either as promising precursors for polymeric carbon nitrides or possibly already on their own, especially since it should be possible to fine-tune properties by preparing solid solutions of these melam complexes, which was exemplarily demonstrated between the CuBr and CuI derivatives. Additionally, the crystal structure of melam's HCl salt was elucidated, which proved to be closely related to that of the coordination complex between melam and CuCl, underlining the similar chemical behavior of Cu+ and H+ toward melam.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Insights into Decoupled Solar Energy Conversion and Charge Storage in a 2D Covalent Organic Framework for Solar Battery Function},

author = {B B Rath and L Fuchs and F Stemmler and A Rodr\'{i}guez-Camargo and Y Wang and M F X Dorfner and J Olbrich and J Van Slageren and F Ortmann and B V Lotsch},

url = {https://doi.org/10.1021/jacs.4c17642},

doi = {10.1021/jacs.4c17642},

issn = {0002-7863},

year  = {2025},

date = {2025-04-28},

journal = {Journal of the American Chemical Society},

abstract = {Decoupling solar energy conversion and storage in a single material offers a great advantage for off-grid applications. Herein, we disclose a two-dimensional naphthalenediimide (NDI)-based covalent organic framework (COF) exhibiting remarkable solar battery performance when used as a photoanode. Light-induced radicals are stabilized within the framework for several hours, offering on-demand charge extraction for electrical energy production. Our study reveals mechanistic insights into the long-term charge stabilization using optical spectroscopy and (photo)electrochemical measurements, in conjunction with density functional theory (DFT) simulations. Among several solvents, water provides the best dielectric screening and energetically favorable proton exchange to stabilize photoinduced radicals for more than 48 h without the need for additional metal cations. This study provides fundamental insights into the optoionic charge storage mechanism in NDI-COF, while introducing a highly tunable, nanoporous material platform that surpasses related materials, such as carbon nitrides, metal\textendashorganic frameworks (MOFs), or metal oxides, in terms of charge storage capacity. This study opens new perspectives for the design of optoionic charge-storing materials and the direct storage of solar energy to overcome the intermittency of solar irradiation.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Upconversion Nanoparticle-Covalent Organic Framework Core\textendashshell Particles as Therapeutic Microrobots Trackable With Optoacoustic Imaging},

author = {D W Kim and P Wrede and A Rodr\'{i}guez-Camargo and Y Chen and N O Dogan and C Gl\"{u}ck and B V Lotsch and D Razansky and M Sitti},

url = {https://doi.org/10.1002/adma.202418425},

doi = {https://doi.org/10.1002/adma.202418425},

issn = {0935-9648},

year  = {2025},

date = {2025-03-07},

journal = {Advanced Materials},

volume = {n/a},

number = {n/a},

pages = {2418425},

abstract = {Abstract Despite the development of various medical imaging contrast agents, integrating contrast signal generation with therapeutic and microrobotic functions remains challenging without complicated fabrication processes. In this study, upconversion nanoparticle-covalent organic framework (UCNP-COF) core?shell sub-micron particles are developed that function as therapeutic microrobots trackable with multi-spectral optoacoustic tomography (MSOT) imaging and can be loaded with desired therapeutic molecular agents in a customizable manner. The mechanism of optoacoustic signal generation in UCNP-COF particles is attributed to the quenching of upconversion luminescence emitted by the UCNPs, which is absorbed by the encapsulating COF and subsequently converted into acoustic waves. Unlike other microparticulate agents previously imaged with MSOT, UCNP-COF particles do not pose concerns about their stability and biocompatibility. Simultaneously, the mesoporous texture of the COF provides a large surface area, allowing for the efficient loading of various drug molecules, which can be released at target sites. Furthermore, the magnetic UCNP-COF Janus particles can be magnetically navigated through in vivo vasculature while being visualized in real-time with volumetric MSOT. This study proposes an approach to design photonic materials with multifunctionality, enabling high-performance medical imaging, drug delivery, and microrobotic manipulation toward their future potential clinical use.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Synthesis of micrometre-thick oriented 2D covalent organic framework films by a kinetic polymerization pathway},

author = {L Cusin and P Cieci\'{o}rski and S Van Gele and F Heck and S Krause and P W Majewski and B V Lotsch and W Danowski and P Samor\`{i}},

url = {https://doi.org/10.1038/s44160-025-00741-7},

doi = {10.1038/s44160-025-00741-7},

issn = {2731-0582},

year  = {2025},

date = {2025-02-20},

journal = {Nature Synthesis},

abstract = {Despite advances in the field of 2D polymerization, the synthesis of high-quality, micrometre-thick films of oriented 2D covalent organic frameworks (COFs) remains challenging. Conventional approaches focusing on thermodynamic control of the polymerization pathway face a detrimental trade-off between orientation and thickness. Here we describe a straightforward method for preparing imine-linked 2D COF films with a near-perfect face-on orientation by leveraging kinetically trapped amorphous 3D covalent adaptable network (CAN) intermediates. These off-pathway intermediates are generated as coatings through solution casting, during which the CANs spontaneously align to relax tensile stresses induced by solvent evaporation. A subsequent lift-off process, followed by an amorphous-to-crystalline transformation under solvothermal conditions, converts the 3D-oriented polymer networks into thermodynamically stable, porous and free-standing 2D COF films. This versatile kinetic trapping strategy is suitable for a range of building blocks and network topologies, constituting a convenient synthetic tool for accessing high-quality, robust, large-area 2D COF films with a strongly aligned polycrystalline structure.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Crystalline porous frameworks based on double extension of metal\textendashorganic and covalent organic linkages},

author = {K Endo and S Canossa and F Heck and D M Proserpio and M S Istek and F Stemmler and J Van Slageren and S Hartmann and A Hartschuh and B V Lotsch},

url = {https://doi.org/10.1038/s44160-024-00719-x},

doi = {10.1038/s44160-024-00719-x},

issn = {2731-0582},

year  = {2025},

date = {2025-01-14},

journal = {Nature Synthesis},

abstract = {Reticular chemistry is a powerful strategy to design materials with fine-tuned chemical functionality and porosity, such as metal\textendashorganic frameworks (MOFs) and covalent organic frameworks (COFs). MOFs typically show high crystallinity due to their reversible coordinative bonds, and the organic backbone of COFs provides chemical stability. Here we synthesize metal\textendashorganic\textendashcovalent\textendashorganic frameworks (MOCOFs) that combine both crystallinity and stability in a single framework by the double extension of metal\textendashorganic and covalent organic linkages. Several MOCOFs are obtained by reaction between a cobalt aminoporphyrin and dialdehydes, which are interconnected by cobalt\textendashamine coordination and imine condensation to form three-dimensional networks. The MOCOFs exhibit chiral topological nets, large surface areas, high crystallinities and high chemical stabilities due to the two types of extended linkages. Thus, MOCOFs present a reticular design strategy that further diversifies the chemical and structural space of porous solids.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Shedding Light on the Active Species in a Cobalt-Based Covalent Organic Framework for the Electrochemical Oxygen Evolution Reaction},

author = {P Hosseini and A Rodr\'{i}guez-Camargo and Y Jiang and S Zhang and C Scheu and L Yao and B V Lotsch and K Tschulik},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/advs.202413555},

doi = {https://doi.org/10.1002/advs.202413555},

issn = {2198-3844},

year  = {2024},

date = {2024-11-26},

journal = {Advanced Science},

volume = {n/a},

number = {n/a},

pages = {2413555},

abstract = {Abstract While considerable efforts have been devoted to developing functionalized covalent organic frameworks (COFs) as oxygen evolution electrocatalysts in recent years, studies related to the investigation of the true catalytically active species for the oxygen evolution reaction (OER) remain lacking in the field. In this work, the active species of a cobalt-functionalized COF (TpBpy-Co) is studied as electrochemical OER catalyst through a series of electrochemical measurements and post-electrolysis characterizations. These results suggest that cobalt oxide-based nanoparticles are formed in TpBpy-Co from Co(II) ions coordinated to the COF backbone when exposing TpBpy-Co to alkaline media, and these newly formed nanoparticles serve as the primary active species for oxygen evolution. The study thus emphasizes that caution is warranted when assessing the catalytic activity of COF electrocatalysts, as the pristine COF may act as the pre-catalyst, with the active species forming only under catalyst operating conditions. Specifically, strong coordination between COFs and metal centers under electrochemical operation conditions is crucial to avoid unintended transformation of COF electrocatalysts. This work thus contributes to the rational development of earth-abundant COF OER catalysts for the production of green hydrogen from renewable resources.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Atomic Insights into the Competitive Edge of Nanosheets Splitting Water},

author = {L J Falling and W Jang and S Laha and T G\"{o}tsch and M W Terban and S Bette and R Mom and J-J Velasco-V\'{e}lez and F Girgsdies and D Teschner and A Tarasov and C-H Chuang and T Lunkenbein and A Knop-Gericke and D Weber and R Dinnebier and B V Lotsch and R Schl\"{o}gl and T E Jones},

url = {https://doi.org/10.1021/jacs.4c10312},

doi = {10.1021/jacs.4c10312},

issn = {0002-7863},

year  = {2024},

date = {2024-10-09},

journal = {Journal of the American Chemical Society},

volume = {146},

number = {40},

pages = {27886-27902},

abstract = {The oxygen evolution reaction (OER) provides the protons for many electrocatalytic power-to-X processes, such as the production of green hydrogen from water or methanol from CO2. Iridium oxohydroxides (IOHs) are outstanding catalysts for this reaction because they strike a unique balance between activity and stability in acidic electrolytes. Within IOHs, this balance varies with the atomic structure. While amorphous IOHs perform best, they are least stable. The opposite is true for their crystalline counterparts. These rules-of-thumb are used to reduce the loading of scarce IOH catalysts and retain the performance. However, it is not fully understood how activity and stability are related at the atomic level, hampering rational design. Herein, we provide simple design rules (Figure 12) derived from the literature and various IOHs within this study. We chose crystalline IrOOH nanosheets as our lead material because they provide excellent catalyst utilization and a predictable structure. We found that IrOOH signals the chemical stability of crystalline IOHs while surpassing the activity of amorphous IOHs. Their dense bonding network of pyramidal trivalent oxygens (μ3Δ-O) provides structural integrity, while allowing reversible reduction to an electronically gapped state that diminishes the destructive effect of reductive potentials. The reactivity originates from coordinative unsaturated edge sites with radical character, i.e., μ1-O oxyls. By comparing to other IOHs and literature, we generalized our findings and synthesized a set of simple rules that allow prediction of stability and reactivity of IOHs from atomistic models. We hope that these rules will inspire atomic design strategies for future OER catalysts.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Active Site Engineering in Reticular Covalent Organic Frameworks for Photocatalytic CO2 Reduction},

author = {B B Rath and S Krause and B V Lotsch},

url = {https://doi.org/10.1002/adfm.202309060},

doi = {https://doi.org/10.1002/adfm.202309060},

issn = {1616-301X},

year  = {2024},

date = {2024-10-01},

journal = {Advanced Functional Materials},

volume = {34},

number = {43},

pages = {2309060},

abstract = {Abstract Photochemical CO2 reduction using ubiquitous sunlight akin to natural photosynthesis is an effective approach for conversion of renewable energy into useful chemical feedstock. Driven by the need for earth-abundant, inexpensive, and sustainable photocatalysts with practical applicability, covalent organic frameworks (COFs) have emerged as a new generation of molecularly defined semiconductors with tunable optoelectronic properties. These reticular frameworks with highly ordered, porous and crystalline structures can be tailor-made by covalently combining organic building blocks to target specific functions. To date, numerous COFs have been reported, which show promising activity for photocatalytic CO2 reduction allowing to derive structure?property?function relationships. In this review, the different reported strategies are comprehensively analyzed and categorized for active site engineering in COF photocatalysts and the synthetic rationale and resulting catalytic activity for each approach are discussed. The recent advancements in terms of tailored photocatalyst design are then critically assessed, aspects of advanced materials characterization are analyzed, and future perspectives and challenges for the field are highlighted.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Decoupling of Light and Dark Reactions in a 2D Niobium Tungstate for Light-Induced Charge Storage and On-Demand Hydrogen Evolution},

author = {Y Wang and Y-T Chan and T Oshima and V Duppel and S Bette and K K\"{u}ster and A Gouder and C Scheurer and B V Lotsch},

url = {https://doi.org/10.1021/jacs.4c04140},

doi = {10.1021/jacs.4c04140},

issn = {0002-7863},

year  = {2024},

date = {2024-09-18},

journal = {Journal of the American Chemical Society},

volume = {146},

number = {37},

pages = {25467-25476},

abstract = {The direct coupling of light harvesting and charge storage in a single material opens new avenues to light storing devices. Here we demonstrate the decoupling of light and dark reactions in the two-dimensional layered niobium tungstate (TBA)+(NbWO6)− for on-demand hydrogen evolution and solar battery energy storage. Light illumination drives Li+/H+ photointercalation into the (TBA)+(NbWO6)− photoanode, leading to small polaron formation assisted by structural distortions on the WOx sublattice, along with a light-induced decrease in material resistance over 2 orders of magnitude compared to the dark. The photogenerated electrons can be extracted on demand to produce solar hydrogen upon the addition of a Pt catalyst. Alternatively, they can be stored for over 20 h under oxygen-free conditions after 365 nm UV illumination for only 10 min, thus featuring a solar battery anode with promising capacity and long-term stability. The optoionic effects described herein offer new insights to overcome the intermittency of solar irradiation, while inspiring applications at the interface of solar energy conversion and energy storage, including solar batteries, “dark” photocatalysis, solar battolyzers, and photomemory devices.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Celebrating Ten Years of Covalent Organic Frameworks for Solar Energy Conversion: Past, Present and Future},

author = {A Rodr\'{i}guez-Camargo and K Endo and B V Lotsch},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/anie.202413096},

doi = {https://doi.org/10.1002/anie.202413096},

issn = {1433-7851},

year  = {2024},

date = {2024-08-21},

journal = {Angewandte Chemie International Edition},

volume = {63},

number = {49},

pages = {e202413096},

abstract = {Abstract Accelerated anthropogenic emission of greenhouse gases due to increasing energy demands has created a negative impact on our planet. Therefore, the replacement of fossil by renewable energy resources has become of paramount interest, both societally and scientifically. It is within this setting that organic photocatalysts have emerged as a new generation of earth-abundant catalysts for the conversion of solar radiation into chemical energy. In 2014, the first example of a covalent organic framework (COF) photocatalyst for the hydrogen evolution reaction was reported by our group, which has not only marked the beginning of COF photocatalysis for solar fuel production but also helped to accelerate research into “soft photocatalysis” based on porous polymers in general. In the last decade, significant progress has been made toward developing COFs as robust, molecularly precise platforms emulating artificial photosynthesis. This mini-review commemorates the 10th anniversary of COF photocatalysis and gives a brief historical overview of the milestones in the field since its inception in 2014. We review milestones in the development of COFs for solar fuel production and related photocatalytic transformations, including hydrogen evolution, oxygen evolution, overall water splitting, CO2 reduction, N2 fixation, oxygen reduction, and alcohol oxidation. We discuss lessons learned for the design of structure-property-function relationships in COF photocatalysts, and future perspectives and challenges for the field of “soft photocatalysis” are given.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Strong angular and spectral narrowing of electroluminescence in an integrated Tamm-plasmon-driven halide perovskite LED},

author = {Z Y Ooi and A Jim\'{e}nez-Solano and K Ga\lkowski and Y Sun and J Ferrer Orri and K Frohna and H Salway and S Kahmann and S Nie and G Vega and S Kar and M P Nowak and S Ma\'{c}kowski and P Nyga and C Ducati and N C Greenham and B V Lotsch and M Anaya and S D Stranks},

url = {https://doi.org/10.1038/s41467-024-49838-1},

doi = {10.1038/s41467-024-49838-1},

issn = {2041-1723},

year  = {2024},

date = {2024-07-10},

journal = {Nature Communications},

volume = {15},

number = {1},

pages = {5802},

abstract = {Next-generation light-emitting applications such as displays and optical communications require judicious control over emitted light, including intensity and angular dispersion. To date, this remains a challenge as conventional methods require cumbersome optics. Here, we report highly directional and enhanced electroluminescence from a solution-processed quasi-2-dimensional halide perovskite light-emitting diode by building a device architecture to exploit hybrid plasmonic-photonic Tamm plasmon modes. By exploiting the processing and bandgap tunability of the halide perovskite device layers, we construct the device stack to optimise both optical and charge-injection properties, leading to narrow forward electroluminescence with an angular full-width half-maximum of 36.6° compared with the conventional isotropic control device of 143.9°, and narrow electroluminescence spectral full-width half-maximum of 12.1 nm. The device design is versatile and tunable to work with emission lines covering the visible spectrum with desired directionality, thus providing a promising route to modular, inexpensive, and directional operating light-emitting devices.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Structures and Ionic Transport Properties of Perovskite-Related BIAIIX3 and BIA2IIX5 Halides},

author = {M A Plass and S Bette and C Schneider and R Eger and B V Lotsch},

url = {https://doi.org/10.1021/acs.chemmater.4c00694},

doi = {10.1021/acs.chemmater.4c00694},

issn = {0897-4756},

year  = {2024},

date = {2024-07-09},

journal = {Chemistry of Materials},

volume = {36},

number = {13},

pages = {6515-6526},

abstract = {The structure family of perovskites and related phases contains a large variety of compounds with versatile properties and applications. While perovskite structures of the AIBIIX3 type usually are categorized based on geometrical considerations like the Goldschmidt tolerance factor, perovskite-related and distorted structure types need to be classified by the more general approach of structure field diagrams. By synthesizing LiSr2X5 with X = Cl, Br, and I, LiSr2Br3.9Cl1.1 and LiEu2X5 with X = Br and I, and LiSm2I5 and LiMIII3 with MII = Sr, Ba, Eu, and Sm as well as KCdBr3, we were able to add several new compounds exhibiting different structure types to the structure field diagrams of perovskite-related ABX3 and BIA2IIX5 compounds. According to the size of lithium ions, these compounds exhibit inverse structure types of BIAIIX3 or BIA2IIX5, where the monovalent lithium ion resides on the lower-coordinated B-site and the divalent metal cation occupies the higher-coordinated A-site. Using in situ variable-temperature powder X-ray diffraction and differential scanning calorimetry, we investigated the relationship between different structure types exemplarily for LiEuI3. Additionally, we examined the ionic transport properties of the different structure types by means of electrochemical impedance spectroscopy and bond valence sum calculations and found restricted dimensionalities of the ion percolation pathways in the investigated structure types, generally limiting the ionic transport properties. Furthermore, the size and softness of the underlying anion lattice, as well as the size and bonding situation of the divalent metal cations, can influence the charge transport properties in LiM2X5 and LiMX3 compounds significantly, where ionic conductivities range between 10\textendash12 and 10\textendash7 S cm\textendash1 at 25 °C.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Sodium Filling in Superadamantoide Na1.36(Si0.86Ga0.14)2As2.98 and the Mixed Valent Arsenidosilicate-Silicide Li1.5Ga0.9Si3.1As4},

author = {M Sch\"{o}neich and L G Balzat and B V Lotsch and D Johrendt},

url = {https://www.mdpi.com/2304-6740/12/6/166},

issn = {2304-6740},

year  = {2024},

date = {2024-06-14},

journal = {Inorganics},

volume = {12},

number = {6},

pages = {166},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Probing Self-Diffusion of Guest Molecules in a Covalent Organic Framework: Simulation and Experiment},

author = {L Grunenberg and C Ke\ssler and T W Teh and R Schuldt and F Heck and J K\"{a}stner and J Gro\ss and N Hansen and B V Lotsch},

url = {https://doi.org/10.1021/acsnano.3c12167},

doi = {10.1021/acsnano.3c12167},

issn = {1936-0851},

year  = {2024},

date = {2024-06-11},

journal = {ACS Nano},

volume = {18},

number = {25},

pages = {16091-16100},

abstract = {Covalent organic frameworks (COFs) are a class of porous materials whose sorption properties have so far been studied primarily by physisorption. Quantifying the self-diffusion of guest molecules inside their nanometer-sized pores allows for a better understanding of confinement effects or transport limitations and is thus essential for various applications ranging from molecular separation to catalysis. Using a combination of pulsed field gradient nuclear magnetic resonance measurements and molecular dynamics simulations, we have studied the self-diffusion of acetonitrile and chloroform in the 1D pore channels of two imine-linked COFs (PI-3-COF) with different levels of crystallinity and porosity. The higher crystallinity and porosity sample exhibited anisotropic diffusion for MeCN parallel to the pore direction, with a diffusion coefficient of Dpar = 6.1(3) × 10\textendash10 m2 s\textendash1 at 300 K, indicating 1D transport and a 7.4-fold reduction in self-diffusion compared to the bulk liquid. This finding aligns with molecular dynamics simulations predicting 5.4-fold reduction, assuming an offset-stacked COF layer arrangement. In the low-porosity sample, more frequent diffusion barriers result in isotropic, yet significantly reduced diffusivities (DB = 1.4(1) × 10\textendash11 m2 s\textendash1). Diffusion coefficients for chloroform at 300 K in the pores of the high- (Dpar = 1.1(2) × 10\textendash10 m2 s\textendash1) and low-porosity (DB = 4.5(1) × 10\textendash12 m2 s\textendash1) samples reproduce these trends. Our multimodal study thus highlights the significant influence of real structure effects such as stacking faults and grain boundaries on the long-range diffusivity of molecular guest species while suggesting efficient intracrystalline transport at short diffusion times.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Downsizing Porphyrin Covalent Organic Framework Particles Using Protected Precursors for Electrocatalytic CO(2) Reduction},

author = {K Endo and A Raza and L Yao and S Van Gele and A Rodr\'{i}guez-Camargo and H A Vignolo-Gonz\'{a}lez and L Grunenberg and B V Lotsch},

doi = {10.1002/adma.202313197},

issn = {0935-9648},

year  = {2024},

date = {2024-05-01},

journal = {Adv Mater},

volume = {36},

number = {19},

pages = {e2313197},

abstract = {Covalent organic frameworks (COFs) are promising electrocatalyst platforms owing to their designability, porosity, and stability. Recently, COFs with various chemical structures are developed as efficient electrochemical CO(2) reduction catalysts. However, controlling the morphology of COF catalysts remains a challenge, which can limit their electrocatalytic performance. Especially, while porphyrin COFs show promising catalytic properties, their particle size is mostly large and uncontrolled because of the severe aggregation of crystallites. In this work, a new synthetic methodology for rationally downsized COF catalyst particles is reported, where a tritylated amine is employed as a novel protected precursor for COF synthesis. Trityl protection provides high solubility to a porphyrin precursor, while its deprotection proceeds in situ under typical COF synthesis conditions. Subsequent homogeneous nucleation and colloidal growth yield smaller COF particles than a conventional synthesis, owing to suppressed crystallite aggregation. The downsized COF particles exhibit superior catalytic performance in electrochemical CO(2) reduction, with higher CO production rate and faradaic efficiency compared to conventional COF particles. The improved performance is attributed to the higher contact area with a conductive agent. This study reveals particle size as an important factor for the evaluation of COF electrocatalysts and provides a strategy to control it.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Covalent Organic Frameworks as Single-Site Photocatalysts for Solar-to-Fuel Conversion},

author = {L Yao and A M P\"{u}tz and H Vignolo-Gonz\'{a}lez and B V Lotsch},

url = {https://doi.org/10.1021/jacs.3c11539},

doi = {10.1021/jacs.3c11539},

issn = {0002-7863},

year  = {2024},

date = {2024-03-28},

urldate = {2024-03-28},

journal = {Journal of the American Chemical Society},

volume = {146},

number = {14},

pages = {9479-9492},

abstract = {Single-site photocatalysts (SSPCs) are well-established as potent platforms for designing innovative materials to accomplish direct solar-to-fuel conversion. Compared to classical inorganic porous materials, such as zeolites and silica, covalent organic frameworks (COFs)─an emerging class of porous polymers that combine high surface areas, structural diversity, and chemical stability─are attractive candidates for SSPCs due to their molecular-level precision and intrinsic light harvesting ability, both amenable to structural engineering. In this Perspective, we summarize the design concepts and state-of-the-art strategies for the construction of COF SSPCs, and we review the development of COF SSPCs and their applications in solar-to-fuel conversion from their inception. Underlying pitfalls concerning photocatalytic characterization are discussed, and perspectives for the future development of this burgeoning field are given.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Influence of Water Content on Speciation and Phase Formation in Zr\textendashPorphyrin-Based MOFs},

author = {C Koschnick and M W Terban and S Canossa and M Etter and R E Dinnebier and B V Lotsch},

url = {https://doi.org/10.1002/adma.202210613},

doi = {https://doi.org/10.1002/adma.202210613},

issn = {0935-9648},

year  = {2024},

date = {2024-03-01},

journal = {Advanced Materials},

volume = {36},

number = {12},

pages = {2210613},

abstract = {Abstract Controlled synthesis of phase-pure metal?organic frameworks (MOFs) is essential for their application in technological areas such as catalysis or gas sorption. Yet, knowledge of their phase formation and growth remain rather limited, particularly with respect to species such as water whose vital role in MOF synthesis is often neglected. As a consequence, synthetic protocols often lack reproducibility when multiple MOFs can form from the same metal source and linker, and phase mixtures are obtained with little or no control over their composition. In this work, the role of water in the formation of the Zr?porphyrin MOF disordered PCN-224 (dPCN-224) is investigated. Through X-ray total scattering and scanning electron microscopy, it is observed that dPCN-224 forms via a metal?organic intermediate that consists of Zr6O4(OH)4 clusters linked by tetrakis(4-carboxy-phenyl)porphyrin molecules. Importantly, water is not only essential to the formation of Zr6O4(OH)4 clusters, but it also plays a primary role in dictating the formation kinetics of dPCN-224. This multidisciplinary approach to studying the speciation of dPCN-224 provides a blueprint for how Zr-MOF synthesis protocols can be assessed and their reproducibility increased, and highlights the importance of understanding the role of water as a decisive component in Zr-MOF formation.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Combining Nitridoborates, Nitrides and Hydrides\textemdashSynthesis and Characterization of the Multianionic Sr6N[BN2]2H3},

author = {S L Wandelt and A Mutschke and D Khalyavin and R Calaminus and J Steinadler and B V Lotsch and W Schnick},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/anie.202313564},

doi = {https://doi.org/10.1002/anie.202313564},

issn = {1433-7851},

year  = {2023},

date = {2023-10-31},

urldate = {2023-10-31},

journal = {Angewandte Chemie International Edition},

volume = {62},

number = {50},

pages = {e202313564},

abstract = {Abstract Multianionic metal hydrides, which exhibit a wide variety of physical properties and complex structures, have recently attracted growing interest. Here we present Sr6N[BN2]2H3, prepared in a solid-state ampoule reaction at 800 °C, as the first combination of nitridoborate, nitride and hydride anions within a single compound. The crystal structure was solved from single-crystal X-ray and neutron powder diffraction data in space group P21/c (no. 14), revealing a three-dimensional network of undulated layers of nitridoborate units, strontium atoms and hydride together with nitride anions. Magic angle spinning (MAS) NMR and vibrational spectroscopy in combination with quantum chemical calculations further confirm the structure model. Electrochemical measurements suggest the existence of hydride ion conductivity, allowing the hydrides to migrate along the layers.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Identifying the active species in a cobalt-based covalent organic framework for the electrochemical oxygen evolution reaction},

author = {P Hosseini and A Rodr\'{i}guez-Camargo and L Yao and B V Lotsch and K Tschulik},

url = {https://chemrxiv.org/engage/chemrxiv/article-details/650cfd18b927619fe79761cb},

doi = {10.26434/chemrxiv-2023-7dl21},

year  = {2023},

date = {2023-09-22},

urldate = {2023-09-22},

abstract = {While considerable efforts have been devoted to developing functionalized covalent organic frameworks (COFs) as oxygen evolution electrocatalysts in recent years, studies related to the identification of the true catalytically active species for the oxygen evolution reaction (OER) remain lacking in the field. In this work, we investigated the active species of a cobalt-functionalized COF (TpBpy-Co) as electrochemical OER catalyst through a series of electrochemical measurements and post-electrolysis characterizations. Our results demonstrate that Co(II) ions, coordinated to the COF backbone, are transformed to cobalt-based nanoparticles when exposing TpBpy-Co to alkaline media. These nanoparticles act as the true active species for oxygen evolution. It remains unclear whether intact TpBpy-Co acts as a secondary catalytic species, due to its structural instability in alkaline electrolyte and its inferred lower catalytic activity compared to cobalt-based nanoparticles. Our results highlight that caution is warranted when identifying the active species for COF electrocatalysts formed under catalyst working conditions. Specifically, strong coordination between COFs and metal centers under electrochemical operation conditions is crucial to avoid unintended transformation of COF electrocatalysts. Our study thus contributes to the rational development of earth-abundant COF OER catalysts for the production of green hydrogen from renewable resources.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Intrinsic disorder in metal\textendashorganic frameworks: an untapped resource for reticular design},

author = {S Canossa and C Koschnick and M Terban and B V Lotsch},

doi = {10.1107/S2053273323082955},

year  = {2023},

date = {2023-08-22},

urldate = {2023-08-22},

journal = {Acta Crystallographica Section A Foundations and Advances},

volume = {79},

pages = {C1326-C1326},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Dissolution and Recrystallization Behavior of Li3PS4 in Different Organic Solvents with a Focus on N-Methylformamide},

author = {K Wissel and L M Riegger and C Schneider and A I Waidha and T Famprikis and Y Ikeda and B Grabowski and R E Dinnebier and B V Lotsch and J Janek and W Ensinger and O Clemens},

url = {https://doi.org/10.1021/acsaem.2c03278},

doi = {10.1021/acsaem.2c03278},

year  = {2023},

date = {2023-08-14},

journal = {ACS Applied Energy Materials},

volume = {6},

number = {15},

pages = {7790-7802},

abstract = {Solid-state batteries can be built based on thiophosphate electrolytes such as β-Li3PS4. For the preparation of these solid electrolytes, various solvent-based routes have been reported. For recycling of end-of-life solid-state batteries based on such thiophosphates, we consider the development of dissolution and recrystallization strategies for the recovery of the model compound β-Li3PS4. We show that recrystallization can only be performed in polar, slightly protic solvents such as N-methylformamide (NMF). The recrystallization is comprehensively studied, showing that it proceeds via an intermediate phase with composition Li3PS4·2NMF, which is structurally characterized. This phase has a high resistivity for the transport of lithium ions and must be removed in order to obtain a recrystallized product with a conductivity similar to the pristine material. Moreover, the recrystallization from solution results in an increase of the amorphous phase fraction next to crystalline β-Li3PS4.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Integrated Solar Batteries: Design and Device Concepts},

author = {A Gouder and B V Lotsch},

url = {https://doi.org/10.1021/acsenergylett.3c00671},

doi = {10.1021/acsenergylett.3c00671},

year  = {2023},

date = {2023-08-11},

journal = {ACS Energy Letters},

volume = {8},

number = {8},

pages = {3343-3355},

abstract = {Solar batteries present an emerging class of devices which enable simultaneous energy conversion and energy storage in one single device. This high level of integration enables new energy storage concepts ranging from short-term solar energy buffers to light-enhanced batteries, thus opening up exciting vistas for decentralized energy storage. The dynamics of this emerging field has engendered a number of different solar battery designs, which significantly differ not only in the charge storage mechanism but also in terms of device design. Herein, we first discuss the fundamental electrochemical signature of these devices, revisit the reported solar battery concepts, and categorize them in a set of five designs by carving out key similarities in how electric and light charging fluxes interact, classifying them either as charge efficient or power efficient charging devices. We then rediscuss solar batteries in the context of our classification scheme and propose design guidelines for solar batteries.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Downsizing Porphyrin Covalent Organic Framework Particles Using Protected Precursors for Electrocatalytic CO2 Reduction},

author = {K Endo and A Raza and L Yao and S Van Gele and A Rodr\'{i}guez-Camargo and H Vignolo-Gonz\'{a}lez and L Grunenberg and B V Lotsch},

url = {https://chemrxiv.org/engage/chemrxiv/article-details/64d12052dfabaf06ffe07a6d},

doi = {10.26434/chemrxiv-2023-skm06},

year  = {2023},

date = {2023-08-08},

urldate = {2023-08-08},

abstract = {Covalent organic frameworks (COFs) are promising electrocatalyst platforms owing to their designability, porosity, and stability. Recently, COFs with various chemical structures were developed as efficient electrochemical CO2 reduction catalysts. However, controlling the morphology of COF catalysts remains a challenge, which can limit their electrocatalytic performance even if the chemical structure is optimally designed. Especially, while metalated porphyrinoids show great promise as catalytically active COF building blocks, their intermolecular stacking and coordination interactions make it difficult to conduct solution-based COF synthesis which can control the particle size dominated by the aggregation of crystallites. In this work, we report a new synthetic methodology for rationally downsized COF catalyst particles, where a tritylated amine is employed as a novel protected precursor for COF synthesis. Trityl protection provides high solubility to a representative cobalt porphyrin precursor, while its deprotection proceeds in situ under typical solvothermal COF synthesis conditions. This colloidal deprotection\textendashpolycondensation process yields smaller COF particles with less crystallite aggregation than a conventional synthesis, maintaining crystallinity and porosity. The downsized COF particles exhibit superior catalytic performance in electrochemical CO2 reduction, with higher CO production rate and faradaic efficiency with similar stability compared to conventional COF particles. The improved performance of downsized COF particles is attributed to the higher contact area with a conductive agent. This study provides a strategy for the preparation of COF electrocatalysts with controlled morphology and enhanced performance and also reveals an important factor in the evaluation of COF electrocatalysts.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Finding Order in Disorder: The Highly Disordered Lithium Oxonitridophosphate Double Salt Li8+xP3O10−xN1+x (x=1.4(5))},

author = {S Schneider and S T Kreiner and L G Balzat and B V Lotsch and W Schnick},

url = {https://chemistry-europe.onlinelibrary.wiley.com/doi/abs/10.1002/chem.202301986},

doi = {https://doi.org/10.1002/chem.202301986},

issn = {0947-6539},

year  = {2023},

date = {2023-07-12},

journal = {Chemistry \textendash A European Journal},

volume = {29},

number = {55},

pages = {e202301986},

abstract = {Abstract The crystalline lithium oxonitridophosphate Li8+xP3O10−xN1+x, was obtained in an ampoule synthesis from P3N5 and Li2O. The compound crystallizes in the triclinic space group P with a=5.125(2)},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Structure and Ionic Conductivity of Li-Disordered Bismuth o-Thiophosphate Li60\textendash3xBi16+x(PS4)36},

author = {M A Plass and M W Terban and T Scholz and I Moudrakovski and V Duppel and R E Dinnebier and B V Lotsch},

url = {https://doi.org/10.1021/acs.inorgchem.3c01028},

doi = {10.1021/acs.inorgchem.3c01028},

issn = {0020-1669},

year  = {2023},

date = {2023-07-10},

journal = {Inorganic Chemistry},

volume = {62},

number = {27},

pages = {10655-10664},

abstract = {The structure of the first lithium-containing bismuth ortho (o)-thiophosphate was determined using a combination of powder X-ray, neutron, and electron diffraction. Li60\textendash3xBi16+x(PS4)36 with x in the range of 4.1\textendash6.5 possesses a complex monoclinic structure [space group C2/c (No. 15)] and a large unit cell with the lattice parameters a = 15.4866 r{A}},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Bridging the Gap between Solar Cells and Batteries: Optical Design of Bifunctional Solar Batteries Based on 2D Carbon Nitrides},

author = {A Gouder and L Yao and Y Wang and F Podjaski and K S Rabinovich and A Jim\'{e}nez-Solano and B V Lotsch},

url = {https://doi.org/10.1002/aenm.202300245},

doi = {https://doi.org/10.1002/aenm.202300245},

issn = {1614-6832},

year  = {2023},

date = {2023-07-01},

journal = {Advanced Energy Materials},

volume = {13},

number = {26},

pages = {2300245},

abstract = {Abstract While solar cell technology is booming, intermittent availability of sunlight motivates new vistas for multifunctional devices capable of energy capture and storage on the same material, i.e., direct or two-electrode bifunctional solar batteries. Herein, simulations and experiments are utilized to take a closer look at efficiency limitations and design considerations, and guidelines are proposed to operate a solar battery comprised of the 2D carbon nitride potassium poly(heptazine imide), K-PHI, as a bifunctional solar battery photoanode in conjunction with the separator poly(N-vinylcarbazole) and cathode poly(3,4-ethylenedioxythiophene):polystyrene sulfonate. An optical design of this device is developed by proposing light absorption in a charge collection layer within the photoanode and calculating photocharging current and charging time as figures of merit. The much larger efficiency of operation via rear illumination for K-PHI layer thicknesses \>200 nm is highlighted and enhancement strategies without modifying the photoactive layer are proposed. Finally, adapted Ragone plots are introduced and it is shown how the solar batteries are capable of improving energy and charge output solely via illumination (for the design under 1 sun, the energy and charge output increase by 60% and 63%, respectively) without modifying the device.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {The Weyl Semimetals MIrTe4 (M = Nb, Ta) as Efficient Catalysts for Dye-Sensitized Hydrogen Evolution},

author = {M Samanta and H Tan and S Laha and H A Vignolo-Gonz\'{a}lez and L Grunenberg and S Bette and V Duppel and P Sch\"{u}tzend\"{u}be and A Gouder and B Yan and B V Lotsch},

url = {https://doi.org/10.1002/aenm.202300503},

doi = {https://doi.org/10.1002/aenm.202300503},

issn = {1614-6832},

year  = {2023},

date = {2023-06-01},

journal = {Advanced Energy Materials},

volume = {13},

number = {24},

pages = {2300503},

abstract = {Abstract The prevalent global energy crisis calls for searching viable pathways for generating green hydrogen as an alternative energy resource. Dye-sensitized photocatalytic water splitting is a feasible solution to produce green hydrogen. However, identifying suitable catalysts has been one of the bottlenecks in driving dye-sensitized photocatalysis efficiently. In this work, a new class of electrocatalysts is reported based on the layered Weyl semimetals MIrTe4 (M = Nb, Ta) for the Eosin Y (EY)-sensitized hydrogen evolution reaction (HER). NbIrTe4 and TaIrTe4 exhibit HER activities of ≈18 000 and 14 000 µmol g?1 respectively, after 10 h of irradiation with visible light. Time-dependent UV-Vis spectroscopy and high-pressure liquid chromatography coupled with mass spectrometry analysis shed light on the reaction dynamics and enable a deeper understanding of the observed trend in hydrogen evolution rates for MIrTe4. MIrTe4 semimetals outperform transition metal-based Weyl semimetals in terms of catalytic HER activity using EY as photosensitizer and triethanolamine as the sacrificial agent. It is hypothesized that the topology-related band inversion in MIrTe4 Weyl semimetals promotes a high density of M d-states near the Fermi level, driving their high catalytic performance. This study introduces a new class of layered Weyl semimetals as efficient catalysts, and provides perspectives for designing topology-enhanced catalysts.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Designing Covalent Organic Framework-Based Light-Driven Microswimmers toward Therapeutic Applications},

author = {V Sridhar and E Yildiz and A Rodr\'{i}guez-Camargo and X Lyu and L Yao and P Wrede and A Aghakhani and B M Akolpoglu and F Podjaski and B V Lotsch and M Sitti},

url = {https://doi.org/10.1002/adma.202301126},

doi = {https://doi.org/10.1002/adma.202301126},

issn = {0935-9648},

year  = {2023},

date = {2023-06-01},

journal = {Advanced Materials},

volume = {35},

number = {25},

pages = {2301126},

abstract = {Abstract While micromachines with tailored functionalities enable therapeutic applications in biological environments, their controlled motion and targeted drug delivery in biological media require sophisticated designs for practical applications. Covalent organic frameworks (COFs), a new generation of crystalline and nanoporous polymers, offer new perspectives for light-driven microswimmers in heterogeneous biological environments including intraocular fluids, thus setting the stage for biomedical applications such as retinal drug delivery. Two different types of COFs, uniformly spherical TABP-PDA-COF sub-micrometer particles and texturally nanoporous, micrometer-sized TpAzo-COF particles are described and compared as light-driven microrobots. They can be used as highly efficient visible-light-driven drug carriers in aqueous ionic and cellular media. Their absorption ranging down to red light enables phototaxis even in deeper and viscous biological media, while the organic nature of COFs ensures their biocompatibility. Their inherently porous structures with ≈2.6 and ≈3.4 nm pores, and large surface areas allow for targeted and efficient drug loading even for insoluble drugs, which can be released on demand. Additionally, indocyanine green (ICG) dye loading in the pores enables photoacoustic imaging, optical coherence tomography, and hyperthermia in operando conditions. This real-time visualization of the drug-loaded COF microswimmers enables unique insights into the action of photoactive porous drug carriers for therapeutic applications.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Postsynthetic Transformation of Imine- into Nitrone-Linked Covalent Organic Frameworks for Atmospheric Water Harvesting at Decreased Humidity},

author = {L Grunenberg and G Savasci and S T Emmerling and F Heck and S Bette and A Cima Bergesch and C Ochsenfeld and B V Lotsch},

url = {https://doi.org/10.1021/jacs.3c02572},

doi = {10.1021/jacs.3c02572},

issn = {0002-7863},

year  = {2023},

date = {2023-05-25},

journal = {Journal of the American Chemical Society},

volume = {145},

number = {24},

pages = {13241-13248},

abstract = {Herein, we report a facile postsynthetic linkage conversion method giving synthetic access to nitrone-linked covalent organic frameworks (COFs) from imine- and amine-linked COFs. The new two-dimensional (2D) nitrone-linked covalent organic frameworks, NO-PI-3-COF and NO-TTI-COF, are obtained with high crystallinity and large surface areas. Nitrone-modified pore channels induce condensation of water vapor at 20% lower humidity compared to their amine- or imine-linked precursor COFs. Thus, the topochemical transformation to nitrone linkages constitutes an attractive approach to postsynthetically fine-tune water adsorption properties in framework materials.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Influence of synthesis and substitution on the structure and ionic transport properties of lithium rare earth metal halides},

author = {M A Plass and S Bette and N Philipp and I Moundrakovski and K K\"{u}ster and R E Dinnebier and B V Lotsch},

url = {http://dx.doi.org/10.1039/D3TA01327H},

doi = {10.1039/D3TA01327H},

issn = {2050-7488},

year  = {2023},

date = {2023-05-11},

journal = {Journal of Materials Chemistry A},

volume = {11},

number = {24},

pages = {13027-13038},

abstract = {Lithium rare earth metal halides have emerged as attractive candidates for solid electrolytes in all-solid-state batteries due to their high ionic conductivities and stability against oxidation. Here, we study their electrochemical properties as a function of the synthesis procedure and post-synthetic treatment and report on the impact of iso- and aliovalent substitutions in the cation and anion sublattices of the lithium rare earth metal iodides Li3MI6. For selected compounds we have investigated the impact of the synthetic approach, i.e. of different solid-state synthesis protocols, and mechanochemical ball-milling without and with post-synthetic calcination on the resulting materials. Lithium rare earth metal iodides obtained from solid-state synthesis generally outperform the mechanochemical synthesized compounds in terms of ionic conductivity and activation energy for ion diffusion, but when mechanochemical ball-milling is combined with a post-synthetic calcination step, these iodides show similar ionic conductivites as their counterparts obtained from conventional solid-state synthesis. Furthermore, we report a series of new Li3MI6 compounds with M = Y, Sm, Gd\textendashLu, partially Cd2+-substituted Li3+yGd1−yCdyI6 and partially Cd2+-, Ca2+- and Zr4+-substituted Li3±yY1−yMII/IVyBr6−xIx phases. Using a combination of ssNMR, EIS and PFG-NMR we reveal the influence of structural parameters such as RE/Li radius ratio, intra-layer cation and stacking fault disorder on the ionic transport properties, obtained from in-depth PXRD analyses. We find that the ionic conductivity is strongly affected by the ratio of the RE/Li radius ratio as well as by the degree of intra-layer cation disorder. It ranges between 3.0 × 10−5 S cm−1 and 4.6 × 10−4 S cm−1 for M = Lu\textendashSm at 20 °C with activation energies between 0.20 eV to 0.33 eV. The combination of partial anion and cation substitution increases the ionic conductivity up to 3.0 × 10−3 S cm−1 and leads to a lower activation energy of 0.17 eV. This study highlights the impact of microstructural effects on the electrochemical properties of solid electrolytes. The rational design and modification of solid electrolytes, along with their comprehensive (micro)structural analysis is thus crucial to optimize their ionic transport properties for applications in all-solid-state batteries.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Nitric Oxide (NO) as a Reagent for Topochemical Framework Transformation and Controlled NO Release in Covalent Organic Frameworks},

author = {S T Emmerling and J Maschita and B V Lotsch},

url = {https://doi.org/10.1021/jacs.2c11967},

doi = {10.1021/jacs.2c11967},

issn = {0002-7863},

year  = {2023},

date = {2023-04-12},

journal = {Journal of the American Chemical Society},

volume = {145},

number = {14},

pages = {7800-7809},

abstract = {Covalent organic frameworks (COFs) have emerged as versatile platforms for the separation and storage of hazardous gases. Simultaneously, the synthetic toolbox to tackle the “COF trilemma” has been diversified to include topochemical linkage transformations and post-synthetic stabilization strategies. Herein, we converge these themes and reveal the unique potential of nitric oxide (NO) as a new reagent for the scalable gas-phase transformation of COFs. Using physisorption and solid-state nuclear magnetic resonance spectroscopy on 15N-enriched COFs, we study the gas uptake capacity and selectivity of NO adsorption and unravel the interactions of NO with COFs. Our study reveals the clean deamination of terminal amine groups on the particle surfaces by NO, exemplifying a unique surface passivation strategy for COFs. We further describe the formation of a NONOate linkage by the reaction of NO with an amine-linked COF, which shows controlled release of NO under physiological conditions. NONOate-COFs thus show promise as tunable NO delivery platforms for bioregulatory NO release in biomedical applications.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Effect of Particle Size and Pressure on the Transport Properties of the Fast Ion Conductor t-Li7SiPS8},

author = {C Schneider and C P Schmidt and A Neumann and M Clausnitzer and M Sadowski and S Harm and C Meier and T Danner and K Albe and A Latz and W A Wall and B V Lotsch},

url = {https://doi.org/10.1002/aenm.202203873},

doi = {https://doi.org/10.1002/aenm.202203873},

issn = {1614-6832},

year  = {2023},

date = {2023-04-01},

journal = {Advanced Energy Materials},

volume = {13},

number = {15},

pages = {2203873},

abstract = {Abstract All-solid-state batteries promise higher energy and power densities as well as increased safety compared to lithium-ion batteries by using non-flammable solid electrolytes and metallic lithium as the anode. Ensuring permanent and close contact between the components and individual particles is crucial for long-term operation of a solid-state cell. This study investigates the particle size dependent compression mechanics and ionic conductivity of the mechanically soft thiophosphate solid electrolyte tetragonal Li7SiPS8 (t-LiSiPS) under pressure. The effect of stack and pelletizing pressure is demonstrated as a powerful tool to influence the microstructure and, hence, ionic conductivity of t-LiSiPS. Heckel analysis for granular powder compression reveals distinct pressure regimes, which differently impact the Li ion conductivity. The pelletizing process is simulated using the discrete element method followed by finite volume analysis to disentangle the effects of pressure-dependent microstructure evolution from atomistic activation volume effects. Furthermore, it is found that the relative density of a tablet is a weaker descriptor for the sample's impedance compared to the particle size distribution. The multiscale experimental and theoretical study thus captures both atomistic and microstructural effects of pressure on the ionic conductivity, thus emphasizing the importance of microstructure, particle size distribution and pressure control in solid electrolytes.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Comprehensive Investigation of Anion Species in Crystalline Li+ ion Conductor Li27−x[P4O7+xN9−x]O3 (x≈1.9(3))},

author = {S Schneider and E-M Wendinger and V Baran and A-K Hatz and B V Lotsch and M Nentwig and O Oeckler and T Br\"{a}uniger and W Schnick},

url = {https://chemistry-europe.onlinelibrary.wiley.com/doi/abs/10.1002/chem.202300174},

doi = {https://doi.org/10.1002/chem.202300174},

issn = {0947-6539},

year  = {2023},

date = {2023-02-21},

journal = {Chemistry \textendash A European Journal},

volume = {29},

number = {27},

pages = {e202300174},

abstract = {Abstract The Li+ ion conductor Li27−x[P4O7+xN9−x]O3 (x≈1.9) has been synthesized from P3N5, Li3N and Li2O in a Ta ampoule at 800 °C under Ar atmosphere. The cubic compound crystallizes in space group with a=12.0106(14) r{A} and Z=4. It contains both non-condensed [PO2N2]5− and [PO3N]4− tetrahedra as well as O2− ions, surrounded by Li+ ions. Charge neutrality is achieved by partial occupancy of Li positions, which was refined with neutron powder diffraction data. Measurements of the partial ionic and electronic conductivity show a total ionic conductivity of 6.6×10−8 S cm−1 with an activation energy of 0.46±0.02 eV and a bulk ionic conductivity of 4×10−6 S cm−1 at 25 °C, which is close to the ionic conductivity of amorphous lithium nitridophosphate. This makes Li27−x[P4O7+xN9−x]O3 an interesting candidate for investigation of structural factors affecting ionic conductivity in lithium oxonitridophosphates.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {An integrated solar battery based on a charge storing 2D carbon nitride},

author = {A Gouder and F Podjaski and A Jim\'{e}nez-Solano and J Kr\"{o}ger and Y Wang and B V Lotsch},

url = {http://dx.doi.org/10.1039/D2EE03409C},

doi = {10.1039/D2EE03409C},

issn = {1754-5692},

year  = {2023},

date = {2023-02-15},

journal = {Energy \& Environmental Science},

volume = {16},

number = {4},

pages = {1520-1530},

abstract = {Solar batteries capable of harvesting sunlight and storing solar energy present an attractive vista to transition our energy infrastructure into a sustainable future. Here we present an integrated, fully earth-abundant solar battery based on a bifunctional (light absorbing and charge storing) carbon nitride (K-PHI) photoanode, combined with organic hole transfer and storage materials. An internal ladder-type hole transfer cascade via a transport layer is used to selectively shuttle the photogenerated holes to the PEDOT:PSS cathode. This concept differs from previous designs such as light-assisted battery schemes or photocapacitors and allows charging with light during both electrical charge and discharge, thus substantially increasing the energy output of the cell. Compared to battery operation in the dark, light-assisted (dis)charging increases charge output by 243%, thereby increasing the electric coulombic efficiency from 68.3% in the dark to 231%, leading to energy improvements of 94.1% under illumination. This concept opens new vistas towards compact, highly integrated devices based on multifunctional, carbon-based electrodes and separators, and paves the way to a new generation of earth-abundant solar batteries.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Monitoring Amine Intercalation in H3Sb3P2O14 Thin Films Based on Real-Time X-ray Diffraction Data Analysis},

author = {M D\"{a}ntl and J Maschita and P Wochner and A Jim\'{e}nez-Solano and H A Vignolo-Gonz\'{a}lez and D Putzky and R E Dinnebier and S Bette and B V Lotsch},

url = {https://doi.org/10.1021/acs.chemmater.2c02394},

doi = {10.1021/acs.chemmater.2c02394},

issn = {0897-4756},

year  = {2023},

date = {2023-02-14},

journal = {Chemistry of Materials},

volume = {35},

number = {3},

pages = {837-845},

abstract = {Thin films comprised of 2D materials have attracted significant attention, as they can be assembled into novel functional materials. However, to further enhance their application scope, it is necessary to harvest the large property space of 2D materials by fine-tuning them on a molecular level, e.g., by intercalation. In order to fully exploit the potential of intercalated 2D materials and design their properties, it is vital to gain a fundamental understanding of the underlying intercalation mechanism. In this work, we present a method for the quantitative analysis of changes in the peak profile and position observed by in situ synchrotron measurements upon the intercalation of the guest molecule into the layered host. We do this by monitoring the intercalation of n-butylamine (3 M in ethanol) into a H3Sb3P2O14 thin film in real time. Our approach includes a state-of-the-art recursive supercell approach that accounts for peak broadening and shifting caused by randomly occurring intercalation, which enabled quantitative Rietveld refinements of the XRD patterns obtained during the interstratification process. This allowed us to reveal the transient formation of intermediates and the critical role of ethanol, which acts as a vehicle for amine intercalation into the layered host.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Morphology Matters: 0D/2D WO3 Nanoparticle-Ruthenium Oxide Nanosheet Composites for Enhanced Photocatalytic Oxygen Evolution Reaction Rates},

author = {H A Vignolo-Gonz\'{a}lez and A Gouder and S Laha and V Duppel and S Carretero-Palacios and A Jim\'{e}nez-Solano and T Oshima and P Sch\"{u}tzend\"{u}be and B V Lotsch},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/aenm.202203315},

doi = {https://doi.org/10.1002/aenm.202203315},

issn = {1614-6832},

year  = {2022},

date = {2022-12-22},

journal = {Advanced Energy Materials},

volume = {n/a},

number = {n/a},

pages = {2203315},

abstract = {Abstract In the field of artificial photosynthesis with semiconductor light harvesters, the default cocatalyst morphologies are isotropic, 0D nanoparticles. Herein, the use of highly anisotropic 2D ruthenium oxide nanosheet (RONS) cocatalysts as an approach to enhance photocatalytic oxygen evolution (OER) rates on commercial WO3 nanoparticles (0D light harvester) is presented. At optimal cocatalyst loadings and identical photocatalysis conditions, WO3 impregnated with RONS (RONS/WO3) shows a fivefold increase in normalized photonic efficiency compared to when it is impregnated with conventional ruthenium oxide (rutile) nanoparticles (RONP/WO3). The superior RONS/WO3 performance is attributed to two special properties of the RONS: i) lower electrochemical water oxidation overpotential for RONS featuring highly active edge sites, and ii) decreased parasitic light absorption on RONS. Evidence is presented that OER photocatalytic performance can be doubled with control of RONS edges and it is shown that compared to WO3 impregnated with RONP, the advantageous optical properties and geometry of RONS decrease the fraction of light absorbed by the cocatalyst, thus reducing the parasitic light absorption on the RONS/WO3 composite. Therefore, the results presented in the current study are expected to promote engineering of cocatalyst morphology as a complementary concept to optimize light harvester-cocatalyst composites for enhanced photocatalytic efficiency.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Structure Determination of the Crystalline LiPON Model Structure Li5+xP2O6−xN1+x with x≈0.9},

author = {S Schneider and L G Balzat and B V Lotsch and W Schnick},

url = {https://chemistry-europe.onlinelibrary.wiley.com/doi/abs/10.1002/chem.202202984},

doi = {https://doi.org/10.1002/chem.202202984},

issn = {0947-6539},

year  = {2022},

date = {2022-11-16},

journal = {Chemistry \textendash A European Journal},

volume = {29},

number = {9},

pages = {e202202984},

abstract = {Abstract Non-crystalline lithium oxonitridophosphate (LiPON) is used as solid electrolyte in all-solid-state batteries. Crystalline lithium oxonitridophosphates are important model structures to retrieve analytical information that can be used to understand amorphous phases better. The new crystalline lithium oxonitridophosphate Li5+xP2O6−xN1+x was synthesized as an off-white powder by ampoule synthesis at 750\textendash800 °C under Ar atmosphere. It crystallizes in the monoclinic space group P21/c with a=15.13087(11) r{A}},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Enhancing Ionic Conductivity by in Situ Formation of Li7SiPS8/Argyrodite Hybrid Solid Electrolytes},

author = {R Calaminus and S Harm and D H Fabini and L G Balzat and A-K Hatz and V Duppel and I Moudrakovski and B V Lotsch},

url = {https://doi.org/10.1021/acs.chemmater.2c00346},

doi = {10.1021/acs.chemmater.2c00346},

issn = {0897-4756},

year  = {2022},

date = {2022-09-13},

journal = {Chemistry of Materials},

volume = {34},

number = {17},

pages = {7666-7677},

abstract = {Solid electrolytes (SEs) with high ionic conductivities are prerequisites to establish solid state batteries on a broad basis. Here we report a novel approach to thiophosphate SEs with improved ionic conductivities based on the in situ formation of LGPS-type tetra-Li7SiPS8/lithium argyrodite Li6PS5X (X= Cl, Br, I) hybrid SEs. Quantitative phase analysis reveals the formation of halogen-poor argyrodites Li6+yPS5+yX1\textendashy next to the tetra-Li7SiPS8 majority phase and an amorphous side phase. EIS measurements indicate ionic conductivities of up to 7 mS cm\textendash1, which exceed those of the parent tetra-Li7SiPS8 and Li6PS5X (X = Cl, Br, I) phases as well as those of simple physical mixtures whose conductivities are well described by the effective medium approximation. In contrast to previous reports, no evidence for halide substitution of the PS43\textendash anions in tetra-Li7SiPS8 was found. Instead, the observed increase in ionic conductivity along with reduced grain boundary resistance is attributed to the directed growth of the tetra-Li7SiPS8 majority phase in the presence of an argyrodite side phase. As a result, a substantially increased isotropic Li diffusion radius is observed by PFG NMR, consistent with both more bulk-like Li transport within secondary particles and with reduced grain boundary resistance through more benign argyrodite interphases as compared to pristine tetra-Li7SiPS8. The microstructural changes induced by hybridization thus provide access to the bulk properties of tetra-Li7SiPS8.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Escaping the horns of the COF dilemma},

author = {L Grunenberg and B V Lotsch},

url = {https://www.sciencedirect.com/science/article/pii/S2590238522003216},

doi = {https://doi.org/10.1016/j.matt.2022.06.026},

issn = {2590-2385},

year  = {2022},

date = {2022-08-03},

journal = {Matter},

volume = {5},

number = {8},

pages = {2482-2484},

abstract = {In Nature, Zhang et al. report a convenient topochemical linkage reconstruction protocol of urea-linked covalent organic frameworks. This procedure adds a new twist to resolving the dilemma between crystallinity and stability in keto-enamine linked COFs.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Guest-responsive thermal expansion in the Zr\textendashporphyrin metal\textendashorganic framework PCN-222},

author = {H L B Bostr\"{o}m and S Bette and S T Emmerling and M W Terban and B V Lotsch},

url = {https://doi.org/10.1063/5.0091091},

doi = {10.1063/5.0091091},

issn = {2166-532X},

year  = {2022},

date = {2022-07-01},

journal = {APL Materials},

volume = {10},

number = {7},

pages = {071106},

abstract = {We use powder x-ray diffraction under variable temperature to study the thermal expansion of the metal\textendashorganic framework (MOF) PCN-222. The thermal expansion increases drastically in magnitude following more aggressive heating, which is rationalized by enhanced flexibility upon guest removal. Moreover, the thermal response strongly depends on the temperature: the volumetric expansivity nearly quadruples and the expansion along c changes sign upon cooling. Our results highlight the large flexibility of MOFs and the role of guest species.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Covalent Organic Framework Nanoplates Enable Solution-Processed Crystalline Nanofilms for Photoelectrochemical Hydrogen Evolution},

author = {L Yao and A Rodr\'{i}guez-Camargo and M Xia and D M\"{u}cke and R Guntermann and Y Liu and L Grunenberg and A Jim\'{e}nez-Solano and S T Emmerling and V Duppel and K Sivula and T Bein and H Qi and U Kaiser and M Gr\"{a}tzel and B V Lotsch},

url = {https://doi.org/10.1021/jacs.2c01433},

doi = {10.1021/jacs.2c01433},

issn = {0002-7863},

year  = {2022},

date = {2022-06-15},

journal = {Journal of the American Chemical Society},

volume = {144},

number = {23},

pages = {10291-10300},

abstract = {As covalent organic frameworks (COFs) are coming of age, the lack of effective approaches to achieve crystalline and centimeter-scale-homogeneous COF films remains a significant bottleneck toward advancing the application of COFs in optoelectronic devices. Here, we present the synthesis of colloidal COF nanoplates, with lateral sizes of ∼200 nm and average heights of 35 nm, and their utilization as photocathodes for solar hydrogen evolution. The resulting COF nanoplate colloid exhibits a unimodal particle-size distribution and an exceptional colloidal stability without showing agglomeration after storage for 10 months and enables smooth, homogeneous, and thickness-tunable COF nanofilms via spin coating. Photoelectrodes comprising COF nanofilms were fabricated for photoelectrochemical (PEC) solar-to-hydrogen conversion. By rationally designing multicomponent photoelectrode architectures including a polymer donor/COF heterojunction and a hole-transport layer, charge recombination in COFs is mitigated, resulting in a significantly increased photocurrent density and an extremely positive onset potential for PEC hydrogen evolution (over +1 V against the reversible hydrogen electrode), among the best of classical semiconductor-based photocathodes. This work thus paves the way toward fabricating solution-processed large-scale COF nanofilms and heterojunction architectures and their use in solar-energy-conversion devices.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Light-driven molecular motors embedded in covalent organic frameworks},

author = {C St\"{a}hler and L Grunenberg and M W Terban and W R Browne and D Doellerer and M Kathan and M Etter and B V Lotsch and B L Feringa and S Krause},

url = {http://dx.doi.org/10.1039/D2SC02282F},

doi = {10.1039/D2SC02282F},

issn = {2041-6520},

year  = {2022},

date = {2022-06-02},

journal = {Chemical Science},

abstract = {The incorporation of molecular machines into the backbone of porous framework structures will facilitate nano actuation, enhanced molecular transport, and other out-of-equilibrium host\textendashguest phenomena in well-defined 3D solid materials. In this work, we detail the synthesis of a diamine-based light-driven molecular motor and its incorporation into a series of imine-based polymers and covalent organic frameworks (COF). We study structural and dynamic properties of the molecular building blocks and derived self-assembled solids with a series of spectroscopic, diffraction, and theoretical methods. Using an acid-catalyzed synthesis approach, we are able to obtain the first crystalline 2D COF with stacked hexagonal layers that contains 20 mol% molecular motors. The COF features a specific pore volume and surface area of up to 0.45 cm3 g−1 and 604 m2 g−1, respectively. Given the molecular structure and bulkiness of the diamine motor, we study the supramolecular assembly of the COF layers and detail stacking disorders between adjacent layers. We finally probe the motor dynamics with in situ spectroscopic techniques revealing current limitations in the analysis of these new materials and derive important analysis and design criteria as well as synthetic access to new generations of motorized porous framework materials.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Photomemristive sensing via charge storage in 2D carbon nitrides},

author = {A Gouder and A Jim\'{e}nez-Solano and N M Vargas-Barbosa and F Podjaski and B V Lotsch},

url = {http://dx.doi.org/10.1039/D2MH00069E},

doi = {10.1039/D2MH00069E},

issn = {2051-6347},

year  = {2022},

date = {2022-04-26},

journal = {Materials Horizons},

volume = {9},

number = {7},

pages = {1866-1877},

abstract = {Photomemristive sensors have the potential to innovate current photo-electrochemical sensors by incorporating new sensing capabilities including non-invasive, wireless and time-delayed (memory) readout. Here we report the charge storing 2D carbon nitride potassium poly(heptazine imide), K-PHI, as a direct photomemristive sensing platform by capitalizing on K-PHI's visible light bandgap, large oxidation potential, and intrinsic optoionic charge storage properties. Utilizing the light-induced charge storage function of K-PHI nanosheets, we demonstrate memory sensing via charge accumulation and present potentiometric, impedimetric and coulometric readouts to write/erase this information from the material, with no additional reagents required. Additionally, wireless colorimetric and fluorometric detection of the charging state of K-PHI nanoparticles is demonstrated, enabling the material's use as particle-based autonomous sensing probe in situ. The various readout options of K-PHI's response enable us to adapt the sensitivities and dynamic ranges without modifying the sensing platform, which is demonstrated using glucose as a model analyte over a wide range of concentrations (50 μM to 50 mM). Since K-PHI is earth abundant, biocompatible, chemically robust and responsive to visible light, we anticipate that the photomemristive sensing platform presented herein opens up memristive and neuromorphic functions.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Superionic Conduction in the Plastic Crystal Polymorph of Na4P2S6},

author = {T Scholz and C Schneider and M W Terban and Z Deng and R Eger and M Etter and R E Dinnebier and P Canepa and B V Lotsch},

url = {https://doi.org/10.1021/acsenergylett.1c02815},

doi = {10.1021/acsenergylett.1c02815},

year  = {2022},

date = {2022-03-22},

journal = {ACS Energy Letters},

volume = {7},

number = {4},

pages = {1403-1411},

abstract = {Sodium thiophosphates are promising materials for large-scale energy storage applications benefiting from high ionic conductivities and the geopolitical abundance of the elements. A representative of this class is Na4P2S6, which currently shows two known polymorphs−α and β. This work describes a third polymorph of Na4P2S6, γ, that forms above 580 °C, exhibits fast-ion conduction with low activation energy, and is mechanically soft. Based on high-temperature diffraction, pair distribution function analysis, thermal analysis, impedance spectroscopy, and ab initio molecular dynamics calculations, the γ-Na4P2S6 phase is identified to be a plastic crystal characterized by dynamic orientational disorder of the P2S64\textendash anions translationally fixed on a body-centered cubic lattice. The prospect of stabilizing plastic crystals at operating temperatures of solid-state batteries, with benefits from their high ionic conductivities and mechanical properties, could have a strong impact in the field of solid-state battery research.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Direct and Linker-Exchange Alcohol-Assisted Hydrothermal Synthesis of Imide-Linked Covalent Organic Frameworks},

author = {J Maschita and T Banerjee and B V Lotsch},

url = {https://doi.org/10.1021/acs.chemmater.1c04051},

doi = {10.1021/acs.chemmater.1c04051},

issn = {0897-4756},

year  = {2022},

date = {2022-02-17},

journal = {Chemistry of Materials},

abstract = {Covalent organic frameworks (COFs) are an extensively studied class of porous materials, which distinguish themselves from other porous polymers in their crystallinity and high degree of modularity, enabling a wide range of applications. However, the established synthetic protocols for the synthesis of stable and crystalline COFs, such as imide-linked COFs, often requires the use of high boiling solvents and toxic catalysts, making their synthesis expensive and environmentally harmful. Herein, we report a new environmentally friendly strategy─an alcohol-assisted hydrothermal polymerization approach (aaHTP) for the synthesis of a wide range of crystalline and porous imide-linked COFs. This method allows us to gain access to new COFs and to avoid toxic solvents by up to 90% through substituting commonly used organic solvent mixtures with water and small amounts of n-alcohols without being restricted to water-soluble linker molecules. Additionally, we use the aaHTP to demonstrate an eco-friendly COF-to-COF transformation of an imine-linked COF into a novel imide-linked COF via linkage replacement, inaccessible using published reaction conditions.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Conductivity Mechanism in Ionic 2D Carbon Nitrides: From Hydrated Ion Motion to Enhanced Photocatalysis},

author = {J Kr\"{o}ger and F Podjaski and G Savasci and I Moudrakovski and A Jim\'{e}nez-Solano and M W Terban and S Bette and V Duppel and M Joos and A Senocrate and R Dinnebier and C Ochsenfeld and B V Lotsch},

url = {https://doi.org/10.1002/adma.202107061},

doi = {https://doi.org/10.1002/adma.202107061},

issn = {0935-9648},

year  = {2022},

date = {2022-02-01},

journal = {Advanced Materials},

volume = {34},

number = {7},

pages = {2107061},

abstract = {Abstract Carbon nitrides are among the most studied materials for photocatalysis; however, limitations arise from inefficient charge separation and transport within the material. Here, this aspect is addressed in the 2D carbon nitride poly(heptazine imide) (PHI) by investigating the influence of various counterions, such as M = Li+, Na+, K+, Cs+, Ba2+, NH4+, and tetramethyl ammonium, on the material's conductivity and photocatalytic activity. These ions in the PHI pores affect the stacking of the 2D layers, which further influences the predominantly ionic conductivity in M-PHI. Na-containing PHI outperforms the other M-PHIs in various relative humidity (RH) environments (0?42%RH) in terms of conductivity, likely due to pore-channel geometry and size of the (hydrated) ion. With increasing RH, the ionic conductivity increases by 4?5 orders of magnitude (for Na-PHI up to 10-5 S cm-1 at 42%RH). At the same time, the highest photocatalytic hydrogen evolution rate is observed for Na-PHI, which is mirrored by increased photogenerated charge-carrier lifetimes, pointing to efficient charge-carrier stabilization by, e.g., mobile ions. These results indicate that also ionic conductivity is an important parameter that can influence the photocatalytic activity. Besides, RH-dependent ionic conductivity is of high interest for separators, membranes, or sensors.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Light-driven carbon nitride microswimmers with propulsion in biological and ionic media and responsive on-demand drug delivery},

author = {V Sridhar and F Podjaski and Y Alapan and J Kr\"{o}ger and L Grunenberg and V Kishore and B V Lotsch and M Sitti},

url = {https://www.science.org/doi/abs/10.1126/scirobotics.abm1421},

doi = {doi:10.1126/scirobotics.abm1421},

year  = {2022},

date = {2022-01-19},

journal = {Science Robotics},

volume = {7},

number = {62},

pages = {eabm1421},

abstract = {We propose two-dimensional poly(heptazine imide) (PHI) carbon nitride microparticles as light-driven microswimmers in various ionic and biological media. Their high-speed (15 to 23 micrometer per second; 9.5 ± 5.4 body lengths per second) swimming in multicomponent ionic solutions with concentrations up to 5 M and without dedicated fuels is demonstrated, overcoming one of the bottlenecks of previous light-driven microswimmers. Such high ion tolerance is attributed to a favorable interplay between the particle’s textural and structural nanoporosity and optoionic properties, facilitating ionic interactions in solutions with high salinity. Biocompatibility of these microswimmers is validated by cell viability tests with three different cell lines and primary cells. The nanopores of the swimmers are loaded with a model cancer drug, doxorubicin (DOX), resulting in a high (185%) loading efficiency without passive release. Controlled drug release is reported under different pH conditions and can be triggered on-demand by illumination. Light-triggered, boosted release of DOX and its active degradation products are demonstrated under oxygen-poor conditions using the intrinsic, environmentally sensitive and light-induced charge storage properties of PHI, which could enable future theranostic applications in oxygen-deprived tumor regions. These organic PHI microswimmers simultaneously address the current light-driven microswimmer challenges of high ion tolerance, fuel-free high-speed propulsion in biological media, biocompatibility, and controlled on-demand cargo release toward their biomedical, environmental, and other potential applications.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Influence of Layer Slipping on Adsorption of Light Gases in Covalent Organic Frameworks: A Combined Experimental and Computational Study},

author = {C Kessler and R Schuldt and S Emmerling and B V Lotsch and J K\"{a}stner and J Gross and N Hansen},

doi = {arXiv:2112.10137v1},

year  = {2021},

date = {2021-12-19},

urldate = {2021-12-19},

journal = {arXiv e-prints},

pages = {arXiv: 2112.10137},

abstract = {Sorption of gases in micro- and mesoporous materials is typically interpreted on the basis of idealized structural models where real structure effects such as defects and disorder are absent. For covalent organic frameworks (COFs) significant discrepancies between measured and simulated adsorption isotherms are often reported but rarely traced back to their origins. This is because little is known about the real structure of COFs and its effect on the sorption properties of these materials. In the present work molecular simulations are used to obtain adsorption isotherms of argon, nitrogen, and carbon dioxide in the COF-LZU1 at various temperatures. The (perfect) model COF has a BET surface that is higher than the experimental BET surface by a factor of approximately 1.33, suggesting defects or inclusions are present in the real structure. We find that the saturation adsorption loading of small gaseous species in COF-LZU1, as determined from grand canonical Monte Carlo simulations, is also higher by approximately the same factor compared to the experimental saturation loading. The influence of interlayer slipping on the shape of the adsorption isotherm and the adsorption capacity is studied. Comparison between simulation and experiment at lower loadings suggests the layers to be shifted instead of perfectly eclipsed. The sensitivity of the adsorption isotherms in this regime towards the underlying framework topology shows that real structure effects have significant influence on the gas uptake. Accounting for layer slipping is important to applications such as catalysis, gas storage and separation.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Olefin Metathesis in Confinement: Towards Covalent Organic Framework Scaffolds for Increased Macrocyclization Selectivity},

author = {S T Emmerling and F Ziegler and F R Fischer and R Schoch and M Bauer and B Plietker and M R Buchmeiser and B V Lotsch},

url = {https://chemistry-europe.onlinelibrary.wiley.com/doi/abs/10.1002/chem.202104108},

doi = {https://doi.org/10.1002/chem.202104108},

issn = {0947-6539},

year  = {2021},

date = {2021-12-09},

urldate = {2021-12-09},

journal = {Chemistry \textendash A European Journal},

volume = {n/a},

number = {n/a},

pages = {e202104108},

abstract = {Abstract Covalent organic frameworks (COFs) offer vast structural and chemical diversity enabling a wide and growing range of applications. While COFs are well-established as heterogeneous catalysts, so far, their high and ordered porosity has scarcely been utilized to its full potential when it comes to spatially confined reactions in COF pores to alter the outcome of reactions. Here, we present a highly porous and crystalline, large-pore COF as catalytic support in α,ω-diene ring-closing metathesis reactions, leading to increased macrocyclization selectivity. COF pore-wall modification by immobilization of a Grubbs-Hoveyda-type catalyst via a mild silylation reaction provides a molecularly precise heterogeneous olefin metathesis catalyst. An increased macro(mono)cyclization (MMC) selectivity over oligomerization (O) for the heterogeneous COF-catalyst (MMC:O=1.35) of up to 51 % compared to the homogeneous catalyst (MMC:O=0.90) was observed along with a substrate-size dependency in selectivity, pointing to diffusion limitations induced by the pore confinement.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Conductivity Mechanism in Ionic 2D Carbon Nitrides: From Hydrated Ion Motion to Enhanced Photocatalysis},

author = {J Kr\"{o}ger and F Podjaski and G Savasci and I Moudrakovski and A Jim\'{e}nez-Solano and M W Terban and S Bette and V Duppel and M Joos and A Senocrate and R Dinnebier and C Ochsenfeld and B V Lotsch},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/adma.202107061},

doi = {https://doi.org/10.1002/adma.202107061},

issn = {0935-9648},

year  = {2021},

date = {2021-12-06},

journal = {Advanced Materials},

volume = {34},

number = {7},

pages = {2107061},

abstract = {Abstract Carbon nitrides are among the most studied materials for photocatalysis; however, limitations arise from inefficient charge separation and transport within the material. Here, this aspect is addressed in the 2D carbon nitride poly(heptazine imide) (PHI) by investigating the influence of various counterions, such as M = Li+, Na+, K+, Cs+, Ba2+, NH4+, and tetramethyl ammonium, on the material's conductivity and photocatalytic activity. These ions in the PHI pores affect the stacking of the 2D layers, which further influences the predominantly ionic conductivity in M-PHI. Na-containing PHI outperforms the other M-PHIs in various relative humidity (RH) environments (0\textendash42%RH) in terms of conductivity, likely due to pore-channel geometry and size of the (hydrated) ion. With increasing RH, the ionic conductivity increases by 4\textendash5 orders of magnitude (for Na-PHI up to 10-5 S cm-1 at 42%RH). At the same time, the highest photocatalytic hydrogen evolution rate is observed for Na-PHI, which is mirrored by increased photogenerated charge-carrier lifetimes, pointing to efficient charge-carrier stabilization by, e.g., mobile ions. These results indicate that also ionic conductivity is an important parameter that can influence the photocatalytic activity. Besides, RH-dependent ionic conductivity is of high interest for separators, membranes, or sensors.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {A flavin-inspired covalent organic framework for photocatalytic alcohol oxidation},

author = {S Trenker and L Grunenberg and T Banerjee and G Savasci and L M Poller and K I M Muggli and F Haase and C Ochsenfeld and B V Lotsch},

url = {http://dx.doi.org/10.1039/D1SC04143F},

doi = {10.1039/D1SC04143F},

issn = {2041-6520},

year  = {2021},

date = {2021-11-15},

urldate = {2021-11-15},

journal = {Chemical Science},

volume = {12},

number = {45},

pages = {15143-15150},

abstract = {Covalent organic frameworks (COFs) offer a number of key properties that predestine them to be used as heterogeneous photocatalysts, including intrinsic porosity, long-range order, and light absorption. Since COFs can be constructed from a practically unlimited library of organic building blocks, these properties can be precisely tuned by choosing suitable linkers. Herein, we report the construction and use of a novel COF (FEAx-COF) photocatalyst, inspired by natural flavin cofactors. We show that the functionality of the alloxazine chromophore incorporated into the COF backbone is retained and study the effects of this heterogenization approach by comparison with similar molecular photocatalysts. We find that the integration of alloxazine chromophores into the framework significantly extends the absorption spectrum into the visible range, allowing for photocatalytic oxidation of benzylic alcohols to aldehydes even with low-energy visible light. In addition, the activity of the heterogeneous COF photocatalyst is less dependent on the chosen solvent, making it more versatile compared to molecular alloxazines. Finally, the use of oxygen as the terminal oxidant renders FEAx-COF a promising and “green” heterogeneous photocatalyst.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Photo-memristive sensing with charge storing 2D carbon nitrides},

author = {A Gouder and A Jimenez-Solano and N M Vargas-Barbosa and F Podjaski and B V Lotsch},

url = {https://arxiv.org/abs/2109.06964},

doi = {arXiv:2109.06964v1},

year  = {2021},

date = {2021-09-14},

journal = {arXiv preprint arXiv:2109.06964},

abstract = {We report the charge storing 2D carbon nitride potassium poly(heptazine imide), K-PHI, as a direct memristive (bio)sensing platform. Memristive devices have the potential to innovate current (bio)electronic systems such as photo-electrochemical sensors by incorporating new sensing capabilities including non-invasive, wireless remote and time-delayed (memory) readout. We demonstrate a direct photomemristive sensing platform that capitalizes on K PHI's visible light bandgap, large oxidation potential and intrinsic optoionic light energy storage properties. Our system simultaneously enables analyte concentration information storage as well as potentiometric, impedimetric and coulo-metric readouts on the same material, with no additional reagents required. Utilizing the light-induced charge storage function of K-PHI, we demonstrate analyte sensing via charge accumulation and present various methods to write/erase this information from the material. Additionally, fully wireless colorimetric and fluorometric detection of the charged state of K-PHI is demonstrated and could facilitate its use as particle-based in-situ sensing probe. The various readout options of the K PHI's response enable us to adapt the sensitivities and dynamic ranges without modifying the sensor. We demonstrate these features using glucose as an example analyte over a wide range of concentrations (50 μM to 50 mM). Moreover, due to the strong oxidative power of K-PHI, this sensing platform is able to detect a large variety of organic or biologically relevant analytes. Since PHI is easily synthesized, based on earth abundant precursors, biocompatible, chemically robust and responsive to visible light, we anticipate that the sensing platform presented herein opens up novel memristive and neuromorphic functions.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Interlayer Interactions as Design Tool for Large-Pore COFs},

author = {S T Emmerling and R Schuldt and S Bette and L Yao and R E Dinnebier and J K\"{a}stner and B V Lotsch},

url = {https://doi.org/10.1021/jacs.1c06518},

doi = {10.1021/jacs.1c06518},

issn = {0002-7863},

year  = {2021},

date = {2021-09-08},

urldate = {2021-09-08},

journal = {Journal of the American Chemical Society},

volume = {143},

number = {38},

pages = {15711-15722},

abstract = {Covalent organic frameworks (COFs) with a pore size beyond 5 nm are still rarely seen in this emerging field. Besides obvious complications such as the elaborated synthesis of large linkers with sufficient solubility, more subtle challenges regarding large-pore COF synthesis, including pore occlusion and collapse, prevail. Here we present two isoreticular series of large-pore imine COFs with pore sizes up to 5.8 nm and correlate the interlayer interactions with the structure and thermal behavior of the COFs. By adjusting interlayer interactions through the incorporation of methoxy groups acting as pore-directing “anchors”, different stacking modes can be accessed, resulting in modified stacking polytypes and, hence, effective pore sizes. A strong correlation between stacking energy toward highly ordered, nearly eclipsed structures, higher structural integrity during thermal stress, and a novel, thermally induced phase transition of stacking modes in COFs was found, which sheds light on viable design strategies for increased structural control and stability in large-pore COFs.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Chemical Stability and Ionic Conductivity of LGPS-Type Solid Electrolyte Tetra-Li7SiPS8 after Solvent Treatment},

author = {A-K Hatz and R Calaminus and J Feijoo and F Treber and J Blahusch and T Lenz and M Reichel and K Karaghiosoff and N M Vargas-Barbosa and B V Lotsch},

url = {https://doi.org/10.1021/acsaem.1c01917},

doi = {10.1021/acsaem.1c01917},

year  = {2021},

date = {2021-08-30},

journal = {ACS Applied Energy Materials},

volume = {4},

number = {9},

pages = {9932-9943},

abstract = {The large-scale production of solid-state batteries necessitates the development of alternative routes for processing air-sensitive thiophosphate-based solid electrolytes. To set a basis for this, we investigate the chemical stability and ionic conductivity of the LGPS-type lithium-ion conductor tetra-Li7SiPS8 (LiSiPS) processed with various organic solvents. We elucidate the nature of colorful polysulfides that arise during solvent treatment and trace back their origin to the dissolution of the Li3PS4-type amorphous side phase typically present in LiSiPS. We find that water and alcohols decompose LiSiPS by the nucleophilic attack into oxygen-substituted thiophosphates and thioethers and propose a reaction mechanism for the latter. Moreover, we confirm that quaternary thiophosphates can be recrystallized from MeOH solutions upon subsequent high-temperature treatment. Aprotic solvents with donor numbers smaller than 15 kcal mol\textendash1 are suitable for wet-processing quaternary thiophosphates because both the crystal structure of the electrolyte and a high ionic conductivity of \>1 mS cm\textendash1 are retained. Using anisole as a case study, we clarify that a residual water content of up to 800 ppm does not lead to a significant deterioration in the ionic conductivity when compared to dry solvents (≤5 ppm). Additionally, we observe a decrease in ionic conductivity with an increasing amount of the solvent residue, which depends not only on the donor number of the solvent but also on the vapor pressure and interactions between the solvent molecules and thiophosphate groups in the solid electrolyte. Thus, optimization of solvent-processing methods of thiophosphate electrolytes is a multifaceted challenge. This work provides transferable insights regarding the stability of LiSiPS against organic solvents that may enable competitive and large-scale thiophosphate-based solid electrolyte processing.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Defying Thermodynamics: Stabilization of Alane Within Covalent Triazine Frameworks for Reversible Hydrogen Storage},

author = {V Stavila and S Li and C Dun and M T Marple and H E Mason and J L Snider and J E Reynolds Iii and F El Gabaly and J D Sugar and C D Spataru and X Zhou and B Dizdar and E H Majzoub and R Chatterjee and J Yano and H Schlomberg and B V Lotsch and J J Urban and B C Wood and M D Allendorf},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/anie.202107507},

doi = {https://doi.org/10.1002/anie.202107507},

issn = {1433-7851},

year  = {2021},

date = {2021-08-29},

journal = {Angewandte Chemie International Edition},

volume = {60},

number = {49},

pages = {25815-25824},

abstract = {Abstract The highly unfavorable thermodynamics of direct aluminum hydrogenation can be overcome by stabilizing alane within a nanoporous bipyridine-functionalized covalent triazine framework (AlH3@CTF-bipyridine). This material and the counterpart AlH3@CTF-biphenyl rapidly desorb H2 between 95 and 154 °C, with desorption complete at 250 °C. Sieverts measurements, 27Al MAS NMR and 27Al1H REDOR experiments, and computational spectroscopy reveal that AlH3@CTF-bipyridine dehydrogenation is reversible at 60 °C under 700 bar hydrogen, \>10 times lower pressure than that required to hydrogenate bulk aluminum. DFT calculations and EPR measurements support an unconventional mechanism whereby strong AlH3 binding to bipyridine results in single-electron transfer to form AlH2(AlH3)n clusters. The resulting size-dependent charge redistribution alters the dehydrogenation/rehydrogenation thermochemistry, suggesting a novel strategy to enable reversibility in high-capacity metal hydrides.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Unveiling the Complex Configurational Landscape of the Intralayer Cavities in a Crystalline Carbon Nitride},

author = {M Pauly and J Kroger and V Duppel and C Murphey and J Cahoon and B V Lotsch and P Maggard},

url = {https://chemrxiv.org/engage/chemrxiv/article-details/6127820165db1ec864a4c3a6},

doi = {10.26434/chemrxiv-2021-90tq7-v2},

year  = {2021},

date = {2021-08-26},

urldate = {2021-08-26},

abstract = {The in-depth understanding of the reported photoelectrochemical properties of the layered carbon nitride, poly(triazine imide)/LiCl (PTI/LiCl), has been limited by the apparent disorder of the Li/H atoms within its framework. To understand and resolve the current structural ambiguities, an optimized one-step flux synthesis (470 oC, 36 h, LiCl/KCl flux) was used to prepare PTI/LiCl and deuterated-PTI/LiCl in high purity. Its structure was characterized by a combination of neutron/X-ray diffraction and transmission electron microscopy. The range of possible Li/H atomic configurations were enumerated for the first time and, combined with total energy calculations, reveals a more complex energetic landscape than previously considered. Experimental data were fitted against all possible structural models, exhibiting the most consistency with a new orthorhombic model (Sp. Grp. Ama2) that also has the lowest total energy. In addition, a new Cu(I)-containing PTI (PTI/CuCl) was prepared with the more strongly scattering Cu(I) cations in place of Li, and which also most closely matched with the partially-disorded structure in Cmc21. Thus, a complex configurational landscape of PTI is revealed to consist of a number of ordered crystalline structures that are new potential synthetic targets, such as with the use of metal-exchange reactions.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Fast Water-Assisted Lithium Ion Conduction in Restacked Lithium Tin Sulfide Nanosheets},

author = {A-K Hatz and I Moudrakovski and S Bette and M W Terban and M Etter and M Joos and N M Vargas-Barbosa and R E Dinnebier and B V Lotsch},

url = {https://doi.org/10.1021/acs.chemmater.1c01755},

doi = {10.1021/acs.chemmater.1c01755},

issn = {0897-4756},

year  = {2021},

date = {2021-08-25},

journal = {Chemistry of Materials},

volume = {33},

number = {18},

pages = {7337-7349},

abstract = {While two-dimensional (2D) materials may preserve some intrinsic properties of the corresponding layered bulk material, new characteristics arise from their pronounced anisotropy or confinement effects. Recently, exceptionally high ionic conductivities were discovered in 2D materials such as graphene oxide and vermiculite. Here, we report on the water-assisted fast conduction of lithium ions in restacked lithium tin sulfide nanosheets. Li0.8Sn0.8S2 exfoliates spontaneously in water and can be restacked into homogeneous films in which the lithium content is decreased, and a partial substitution of sulfur with hydroxyl groups takes place. Using a recursive supercell refinement approach in reciprocal space along with real-space pair distribution function analysis, we describe restacked lithium tin sulfide as a partially turbostratically disordered material composed of lithium-containing and lithium-depleted layers. In humid air, the material takes up multiple layers of water that coordinate lithium ions in the space between the layers, increasing the stacking distance and screening the interaction between lithium ions and the anionic layers. This results in a 1000-fold increase in ionic conductivity up to 47 mS cm\textendash1 at high humidities. Orientation-dependent impedance spectroscopy suggests a facile in-plane conduction and a hindered out-of-plane conduction. Pulsed field gradient nuclear magnetic resonance spectroscopy reveals a fast, simultaneous diffusion of a majority and a minority species for both 7Li and 1H, suggesting water-assisted lithium diffusion to be at play. This study enlarges the family of nanosheet-based ionic conductors and helps to rationalize the transport mechanism of lithium ions enabled by hydration in a nanoconfined 2D space.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Impact of hydration on ion transport in Li2Sn2S5·xH2O},

author = {M Joos and C Schneider and A M\"{u}nchinger and I Moudrakovski and R Usiskin and J Maier and B V Lotsch},

url = {http://dx.doi.org/10.1039/D1TA04736A},

doi = {10.1039/D1TA04736A},

issn = {2050-7488},

year  = {2021},

date = {2021-07-23},

journal = {Journal of Materials Chemistry A},

volume = {9},

number = {30},

pages = {16532-16544},

abstract = {This work investigates the structure and transport properties of the layered material Li2Sn2S5·xH2O. The anhydrous phase shows a room-temperature Li+ diffusivity below 10−9 cm2 s−1 and conductivity below 10−5 S cm−1. Upon exposure to humidity, water intercalates between the layers and increases the interlayer distance, inducing first-order transitions to a hydrated phase (x ≈ 2\textendash4) and then to a second hydrated phase (x ≈ 8\textendash10). The latter is soft and sticky but remains solid. Diffusion of both Li+ ions and H2O remains predominantly two-dimensional under all conditions. The Li+ diffusivity and conductivity both increase by three orders of magnitude upon hydration, reaching values of 5 × 10−7 cm2 s−1 and 10−2 S cm−1 in the second hydrate. These transport rates are extraordinary for a solid electrolyte and approach what is typically seen in aqueous solutions. The material Li2Sn2S5·xH2O thus bridges the gap between a hydrated solid electrolyte and a confined liquid electrolyte, which is scientifically interesting and potentially useful in battery applications. In the light of these findings, a previous work on Li2Sn2S5 from our groups is revisited.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {A Tour-Guide through Carbon Nitride-Land: Structure- and Dimensionality-Dependent Properties for Photo(Electro)Chemical Energy Conversion and Storage},

author = {V W-H Lau and B V Lotsch},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/aenm.202101078},

doi = {https://doi.org/10.1002/aenm.202101078},

issn = {1614-6832},

year  = {2021},

date = {2021-07-11},

journal = {Advanced Energy Materials},

volume = {12},

number = {4},

pages = {2101078},

abstract = {Abstract Despite the explosion in the number of publications on the graphitic carbon nitride family of materials, much still remains unknown about their structure and the underlying properties responsible for their various applications. This critical review covers the state-of-the-art in the understanding of their structure\textendashproperty\textendashphotocatalysis relationship, from their molecular constituents to stacking as a (quasi) two-dimensional structure, highlighting the areas in which there is wide agreement and those still unresolved. This review first recounts how the structural understanding of these materials has evolved since the 19th century, followed by a commentary on the best practice for unambiguously characterizing their molecular structure and two-dimensional stacking arrangements. The recent literature is then examined to elucidate how individual molecular moieties affect their various material properties, particularly their chemical and opto\textendashelectronic properties, carrier dynamics, and catalytic reactivity, and how their use for energy applications can be impacted by the structural features across each dimension. Lastly, the translation of the aforementioned fundamental insights to rational molecular design is demonstrated, highlighting the synthesis of heptazine-based materials for order-of-magnitude improvement in photocatalytic reactivity, as well as the unusual phenomenon of stabilization of light-induced electrons, an effect currently exploited for a new paradigm in solar energy storage.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {In situ monitoring of mechanochemical covalent organic framework formation reveals templating effect of liquid additive},

author = {S T Emmerling and L S Germann and P A Julien and I Moudrakovski and M Etter and T Fri\v{s}\v{c}i\'{c} and R E Dinnebier and B V Lotsch},

url = {https://www.sciencedirect.com/science/article/pii/S2451929421002138},

doi = {https://doi.org/10.1016/j.chempr.2021.04.012},

issn = {2451-9294},

year  = {2021},

date = {2021-06-10},

journal = {Chem},

volume = {7},

number = {6},

pages = {1639-1652},

abstract = {Summary Covalent organic frameworks (COFs) have emerged as a new class of molecularly precise, porous functional materials characterized by broad structural and chemical versatility, with a diverse range of applications. Despite their increasing popularity, fundamental aspects of COF formation are poorly understood, lacking profound experimental insights into their assembly. Here, we use a combination of in situ X-ray powder diffraction and Raman spectroscopy to elucidate the reaction mechanism of mechanochemical synthesis of imine COFs, leading to the observation of key reaction intermediates that offer direct experimental evidence of framework templating through liquid additives. Moreover, the solid-state catalyst scandium triflate is instrumental in directing the reaction kinetics and mechanism, yielding COFs with crystallinity and porosity on par with solvothermal products. This work provides the first experimental evidence of solvent-based COF templating and is a significant advancement in mechanistic understanding of mechanochemistry as a green route for COF synthesis.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Understanding disorder and linker deficiency in porphyrinic zirconium-based metal\textendashorganic frameworks by resolving the Zr8O6 cluster conundrum in PCN-221},

author = {C Koschnick and R St\"{a}glich and T Scholz and M W Terban and A Von Mankowski and G Savasci and F Binder and A Sch\"{o}kel and M Etter and J Nuss and R Siegel and L S Germann and C Ochsenfeld and R E Dinnebier and J Senker and B V Lotsch},

url = {https://doi.org/10.1038/s41467-021-23348-w},

doi = {10.1038/s41467-021-23348-w},

issn = {2041-1723},

year  = {2021},

date = {2021-05-25},

journal = {Nature Communications},

volume = {12},

number = {1},

pages = {3099},

abstract = {Porphyrin-based metal\textendashorganic frameworks (MOFs), exemplified by MOF-525, PCN-221, and PCN-224, are promising systems for catalysis, optoelectronics, and solar energy conversion. However, subtle differences between synthetic protocols for these three MOFs give rise to vast discrepancies in purported product outcomes and description of framework topologies. Here, based on a comprehensive synthetic and structural analysis spanning local and long-range length scales, we show that PCN-221 consists of Zr6O4(OH)4 clusters in four distinct orientations within the unit cell, rather than Zr8O6 clusters as originally published, and linker vacancies at levels of around 50%, which may form in a locally correlated manner. We propose disordered PCN-224 (dPCN-224) as a unified model to understand PCN-221, MOF-525, and PCN-224 by varying the degree of orientational cluster disorder, linker conformation and vacancies, and cluster\textendashlinker binding. Our work thus introduces a new perspective on network topology and disorder in Zr-MOFs and pinpoints the structural variables that direct their functional properties.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Beyond templating: Electronic structure impacts of aromatic cations in organic\textendashinorganic antimony chlorides},

author = {J Blahusch and D H Fabini and A Jim\'{e}nez-Solano and B V Lotsch},

url = {https://doi.org/10.1002/zaac.202000484},

doi = {https://doi.org/10.1002/zaac.202000484},

issn = {0044-2313},

year  = {2021},

date = {2021-04-26},

journal = {Zeitschrift f\"{u}r anorganische und allgemeine Chemie},

volume = {647},

number = {8},

pages = {857-866},

abstract = {Abstract Organic cations influence the crystal packing and, less commonly, the electronic structure of hybrid organic?inorganic materials. Two new hybrid compounds prepared from solution, (PEA)SbCl6 and (PEA)4Sb2Cl12 (PEA=phenylethylammonium), demonstrate how the aromatic PEA cation modifies the crystal and electronic structures relative to inorganic antimony chlorides. In (PEA)SbCl6 the ethylammonium conformation results in a polar and chiral crystal structure, and the bandgap is characterized by organic-inorganic charge transfer. In the mixed-valence (PEA)4SbIIISbVCl12 the structure is a uniaxial elongation of that of inorganic analogs and the optoelectronic properties combine features of intervalence charge transfer and organic?inorganic charge transfer.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Biocompatible carbon nitride-based light-driven microswimmer propulsion in biological and ionic media with responsive on-demand drug delivery},

author = {V Sridhar and F Podjaski and Y Alapan and J Kr\"{o}ger and L Grunenberg and V Kishore and B V Lotsch and M Sitti},

url = {https://arxiv.org/abs/2103.17026},

doi = {arXiv:2103.17026v1},

year  = {2021},

date = {2021-03-31},

journal = {arXiv preprint arXiv:2103.17026},

abstract = {We propose two-dimensional organic poly(heptazine imide) (PHI) carbon nitride microparticles as light-driven microswimmers in various ionic and biological media. Their demonstrated high-speed (15-23 μm/s) swimming in multi-component ionic solutions with concentrations up to 1 M and without dedicated fuels is unprecedented, overcoming one of the bottlenecks of previous light-driven microswimmers. Such high ion tolerance is attributed to a favorable interplay between the particle's textural and structural nanoporosity and optoionic properties, facilitating ionic interactions in solutions with high salinity. Biocompatibility of the microswimmers is validated by cell viability tests with three different cell types and primary cells. The nanopores of the swimmers are loaded with a model cancer drug, doxorubicin (DOX), in high (185%) loading efficiency without passive release. Controlled drug release is reported in different pH conditions and can be triggered on-demand also by illumination. Light-triggered, boosted release of DOX and its active degradation products is demonstrated in oxygen-poor conditions using the intrinsic, environmentally sensitive and light-induced charge storage properties of PHI, which could enable future theranostic applications in oxygen-deprived tumor regions. These organic PHI microswimmers simultaneously solve the current light-driven microswimmer challenges of high ion tolerance, fuel-free high-speed propulsion in biological media, biocompatibility and controlled on-demand cargo release towards their biomedical, environmental and other potential future applications.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Phase formation through synthetic control: polymorphism in the sodium-ion solid electrolyte Na4P2S6},

author = {T Scholz and C Schneider and R Eger and V Duppel and I Moudrakovski and A Schulz and J Nuss and B V Lotsch},

url = {http://dx.doi.org/10.1039/D0TA11008F},

doi = {10.1039/D0TA11008F},

issn = {2050-7488},

year  = {2021},

date = {2021-03-10},

journal = {Journal of Materials Chemistry A},

volume = {9},

number = {13},

pages = {8692-8703},

abstract = {The development of all-solid-state sodium batteries for scalable energy storage solutions requires fast sodium conducting solid electrolytes. To fast-track their discovery, candidate materials need to be identified that are synthesized from abundant resources via cheap and green synthesis routes. Their ion conducting mechanism has to be understood and adapted to meet the stringent requirements for long-term operation in all-solid-state batteries. Here, structure and properties of the sodium hexathiohypodiphosphate Na4P2S6 obtained by two different synthesis methods are compared: a solid-state reaction and a precipitation route from aqueous solution. Combined investigations using powder X-ray diffraction (PXRD), precession electron diffraction (PED), differential scanning calorimetry (DSC), solid-state nuclear magnetic resonance spectroscopy (ssNMR), and Raman spectroscopy reveal that the solid-state synthesized material is characterized by a Na+ and vacancy disorder-driven enantiotropic phase transition at 160 °C (α- to β-Na4P2S6), which is accompanied by a symmetry change of the P2S64− anion. Precipitated Na4P2S6 already crystallizes in a β-like polymorph at room temperature, likely assisted by inter- and intralayer defects. Bond-valence and nudged elastic band (NEB) calculations were employed to identify a low energy, 2D conduction network in β-Na4P2S6, suggesting facile 2D long-range Na+ diffusion. Electrochemical impedance spectroscopy reveals a higher ionic conductivity at room temperature in precipitated β-like Na4P2S6 (2 × 10−6 S cm−1) compared to the solid-state α polymorph (7 × 10−7 S cm−1). The activation energy is around 0.4 eV for both materials. The findings highlight that even subtle structural changes can significantly impact the sodium-ion diffusion in solid electrolytes and at the same time reveal an intricate interplay between phase formation and synthetic control.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Amine-Linked Covalent Organic Frameworks as a Platform for Postsynthetic Structure Interconversion and Pore-Wall Modification},

author = {L Grunenberg and G Savasci and M W Terban and V Duppel and I Moudrakovski and M Etter and R E Dinnebier and C Ochsenfeld and B V Lotsch},

url = {https://doi.org/10.1021/jacs.0c12249},

doi = {10.1021/jacs.0c12249},

issn = {0002-7863},

year  = {2021},

date = {2021-02-24},

urldate = {2021-02-24},

journal = {Journal of the American Chemical Society},

volume = {143},

number = {9},

pages = {3430-3438},

abstract = {Covalent organic frameworks have emerged as a powerful synthetic platform for installing and interconverting dedicated molecular functions on a crystalline polymeric backbone with atomic precision. Here, we present a novel strategy to directly access amine-linked covalent organic frameworks, which serve as a scaffold enabling pore-wall modification and linkage-interconversion by new synthetic methods based on Leuckart\textendashWallach reduction with formic acid and ammonium formate. Frameworks connected entirely by secondary amine linkages, mixed amine/imine bonds, and partially formylated amine linkages are obtained in a single step from imine-linked frameworks or directly from corresponding linkers in a one-pot crystallization-reduction approach. The new, 2D amine-linked covalent organic frameworks, rPI-3-COF, rTTI-COF, and rPy1P-COF, are obtained with high crystallinity and large surface areas. Secondary amines, installed as reactive sites on the pore wall, enable further postsynthetic functionalization to access tailored covalent organic frameworks, with increased hydrolytic stability, as potential heterogeneous catalysts.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Transfer of 1D Photonic Crystals via Spatially Resolved Hydrophobization},

author = {M D\"{a}ntl and S Guderley and K Szendrei-Temesi and D Chatzitheodoridou and P Ganter and A Jim\'{e}nez-Solano and B V Lotsch},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/smll.202007864},

doi = {https://doi.org/10.1002/smll.202007864},

issn = {1613-6810},

year  = {2021},

date = {2021-02-15},

journal = {Small},

volume = {17},

number = {12},

pages = {2007864},

abstract = {Abstract 1D photonic crystals (1DPCs) are well known from a variety of applications ranging from medical diagnostics to optical fibers and optoelectronics. However, large-scale application is still limited due to complex fabrication processes and bottlenecks in transferring 1DPCs to arbitrary substrates and pattern creation. These challenges were addressed by demonstrating the transfer of millimeter- to centimeter-scale 1DPC sensors comprised of alternating layers of H3Sb3P2O14 nanosheets and TiO2 nanoparticles based on a non-invasive chemical approach. By depositing the 1DPC on a sacrificial layer of lithium tin sulfide nanosheets and hydrophobizing only the 1DPC by intercalation of n-octylamine via the vapor phase the 1DPC can be detached from the substrate by immersing the sample in water. Upon exfoliation of the hydrophilic sacrificial layer, the freestanding 1DPC remains at the water\textendashair interface. In a second step, it can be transferred to arbitrary surfaces such as curved glass. In addition, the transfer of patterned 1DPCs is demonstrated by combining the sacrificial layer approach with area-resolved intercalation and etching. The fact that the sensing capability of the 1DPC is not impaired and can be modified after transfer renders this method a generic platform for the fabrication of photonic devices.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Photocatalytic Hydrogen Evolution: Interfacial Engineering for Improved Photocatalysis in a Charge Storing 2D Carbon Nitride: Melamine Functionalized Poly(heptazine imide) (Adv. Energy Mater. 6/2021)},

author = {J Kr\"{o}ger and A Jim\'{e}nez-Solano and G Savasci and P Rov\'{o} and I Moudrakovski and K K\"{u}ster and H Schlomberg and H A Vignolo-Gonz\'{a}lez and V Duppel and L Grunenberg and C B Dayan and M Sitti and F Podjaski and C Ochsenfeld and B V Lotsch},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/aenm.202170028},

doi = {https://doi.org/10.1002/aenm.202170028},

issn = {1614-6832},

year  = {2021},

date = {2021-02-11},

journal = {Advanced Energy Materials},

volume = {11},

number = {6},

pages = {2170028},

abstract = {In article number 2003016, Bettina V. Lotsch and co-workers demonstrate that covalent surface modifications of the 2D carbon nitride poly(heptazine imide) with melamine groups strongly influence its polarity and photo(electrochemical) properties. This potent tuning pathway also results in the boosting of photocatalytic hydrogen evolution due to increased donor interactions and enhanced hole extraction.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Examination of possible high-pressure candidates of SnTiO3: The search for novel ferroelectric materials},

author = {F Pielnhofer and L Diehl and A Jim\'{e}nez-Solano and A Bussmann-Holder and J C Sch\"{o}n and B V Lotsch},

url = {https://aip.scitation.org/doi/abs/10.1063/5.0029968},

doi = {10.1063/5.0029968},

year  = {2021},

date = {2021-02-02},

journal = {APL Materials},

volume = {9},

number = {2},

pages = {021103},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Relaxed Current Matching Requirements in Highly Luminescent Perovskite Tandem Solar Cells and Their Fundamental Efficiency Limits},

author = {A R Bowman and F Lang and Y-H Chiang and A Jim\'{e}nez-Solano and K Frohna and G E Eperon and E Ruggeri and M Abdi-Jalebi and M Anaya and B V Lotsch and S D Stranks},

url = {https://doi.org/10.1021/acsenergylett.0c02481},

doi = {10.1021/acsenergylett.0c02481},

year  = {2021},

date = {2021-01-22},

journal = {ACS Energy Letters},

volume = {6},

number = {2},

pages = {612-620},

abstract = {Perovskite-based tandem solar cells are of increasing interest as they approach commercialization. Here we use experimental parameters from optical spectroscopy measurements to calculate the limiting efficiency of perovskite\textendashsilicon and all-perovskite two-terminal tandems, employing currently available bandgap materials, as 42.0% and 40.8%, respectively. We show luminescence coupling between subcells (the optical transfer of photons from the high-bandgap to low-bandgap subcell) relaxes current matching when the high-bandgap subcell is a luminescent perovskite. We calculate that luminescence coupling becomes important at charge trapping rates (≤106 s\textendash1) already being achieved in relevant halide perovskites. Luminescence coupling increases flexibility in subcell thicknesses and tolerance to different spectral conditions. For maximal benefit, the high-bandgap subcell should have the higher short-circuit current under average spectral conditions. This can be achieved by reducing the bandgap of the high-bandgap subcell, allowing wider, unstable bandgap compositions to be avoided. Lastly, we visualize luminescence coupling in an all-perovskite tandem through cross-section luminescence imaging.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Morphology Control in 2D Carbon Nitrides: Impact of Particle Size on Optoelectronic Properties and Photocatalysis},

author = {J Kr\"{o}ger and A Jim\'{e}nez-Solano and G Savasci and V W H Lau and V Duppel and I Moudrakovski and K K\"{u}ster and T Scholz and A Gouder and M-L Schreiber and F Podjaski and C Ochsenfeld and B V Lotsch},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/adfm.202102468},

doi = {https://doi.org/10.1002/adfm.202102468},

issn = {1616-301X},

year  = {2021},

date = {2021-01-01},

urldate = {2021-01-01},

journal = {Advanced Functional Materials},

volume = {31},

number = {28},

pages = {2102468},

abstract = {Abstract The carbon nitride poly(heptazine imide), PHI, has recently emerged as a powerful 2D carbon nitride photocatalyst with intriguing charge storing ability. Yet, insights into how morphology, particle size, and defects influence its photophysical properties are virtually absent. Here, ultrasonication is used to systematically tune the particle size as well as concentration of surface functional groups and study their impact. Enhanced photocatalytic activity correlates with an optimal amount of those defects that create shallow trap states in the optical band gap, promoting charge percolation, as evidenced by time-resolved photoluminescence spectroscopy, charge transport studies, and quantum-chemical calculations. Excessive amounts of terminal defects can act as recombination centers and hence, decrease the photocatalytic activity for hydrogen evolution. Re-agglomeration of small particles can, however, partially restore the photocatalytic activity. The type and amount of trap states at the surface can also influence the deposition of the co-catalyst Pt, which is used in hydrogen evolution experiments. Optimized conditions entail improved Pt distribution, as well as enhanced wettability and colloidal stability. A description of the interplay between these effects is provided to obtain a holistic picture of the size\textendashproperty\textendashactivity relationship in nanoparticulate PHI-type carbon nitrides that can likely be generalized to related photocatalytic systems.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Interfacial Engineering for Improved Photocatalysis in a Charge Storing 2D Carbon Nitride: Melamine Functionalized Poly(heptazine imide)},

author = {J Kr\"{o}ger and A Jim\'{e}nez-Solano and G Savasci and P Rov\'{o} and I Moudrakovski and K K\"{u}ster and H Schlomberg and H A Vignolo-Gonz\'{a}lez and V Duppel and L Grunenberg and C B Dayan and M Sitti and F Podjaski and C Ochsenfeld and B V Lotsch},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/aenm.202003016},

doi = {https://doi.org/10.1002/aenm.202003016},

issn = {1614-6832},

year  = {2020},

date = {2020-12-21},

journal = {Advanced Energy Materials},

volume = {11},

number = {6},

pages = {2003016},

abstract = {Abstract Carbon nitrides constitute a class of earth-abundant polymeric semiconductors, which have high potential for tunability on a molecular level, despite their high chemical and thermal inertness. Here the first postsynthetic modification of the 2D carbon nitride poly(heptazine imide) (PHI) is reported, which is decorated with terminal melamine (Mel) moieties by a functional group interconversion. The covalent attachment of this group is verified based with a suite of spectroscopic and microscopic techniques supported by quantum\textendashchemical calculations. Using triethanolamine as a sacrificial electron donor, Mel-PHI outperforms most other carbon nitrides in terms of hydrogen evolution rate (5570 µmol h−1 g−1), while maintaining the intrinsic light storing properties of PHI. The origin of the observed superior photocatalytic performance is traced back to a modified surface electronic structure and enhanced interfacial interactions with the amphiphile triethanolamine, which imparts improved colloidal stability to the catalyst particles especially in contrast to methanol used as donor. However, this high activity can be limited by oxidation products of donor reversibly building up at the surface, thus blocking active centers. The findings lay out the importance of surface functionalization to engineer the catalyst\textendashsolution interface, an underappreciated tuning parameter in photocatalytic reaction design.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Optoelectronics Meets Optoionics: Light Storing Carbon Nitrides and Beyond},

author = {F Podjaski and B V Lotsch},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/aenm.202003049},

doi = {https://doi.org/10.1002/aenm.202003049},

issn = {1614-6832},

year  = {2020},

date = {2020-11-23},

journal = {Advanced Energy Materials},

volume = {11},

number = {4},

pages = {2003049},

abstract = {Abstract Known for decades, Liebig's carbon nitrides have evolved into a burgeoning class of macromolecular semiconductors over the past 10+ years, front and center of many efforts revolving around the discovery of resource-efficient and high-performance photocatalysts for solar fuel generation. The recent discovery of a new class of “ionic” 2D carbon nitrides\textemdashpoly(heptazine imide) (PHI)\textemdashhas given new momentum to this field, driven both by unconventional properties and the prospect of new applications at the intersection between solar energy conversion and electrochemical energy storage. In this essay, key concepts of the emerging field of optoionics are delineated and the “light storing” ability of PHI-type carbon nitrides is rationalized by an intricate interplay between their optoelectronic and optoionic properties. Based on these insights, key characteristics and general principles for the de novo design of optoionic materials across the periodic table are derived, opening up new research avenues such as “dark photocatalysis”, direct solar batteries, light-driven autonomous systems, and photomemristive devices.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Solving the COF trilemma: towards crystalline, stable and functional covalent organic frameworks},

author = {F Haase and B V Lotsch},

url = {http://dx.doi.org/10.1039/D0CS01027H},

doi = {10.1039/D0CS01027H},

issn = {0306-0012},

year  = {2020},

date = {2020-11-06},

journal = {Chemical Society Reviews},

abstract = {Covalent organic frameworks (COFs) have entered the stage as a new generation of porous polymers which stand out by virtue of their crystallinity, diverse framework topologies and accessible pore systems. An important \textendash but still underdeveloped \textendash feature of COFs is their potentially superior stability in comparison to other porous materials. Achieving COFs which are simultaneously crystalline, stable, and functional is still challenging as reversible bond formation is one of the prime prerequisites for the crystallization of COFs. However, as the COF field matures new strategies have surfaced that bypass this crystallinity \textendash stability dichotomy. Three major approaches for obtaining both stable and crystalline COFs have taken form in recent years: Tweaking the reaction conditions for reversible linkages, separating the order inducing step and the stability inducing step, and controlling the structural degrees of freedom during assembly and in the final COF. This review discusses rational approaches to stability and crystallinity engineering in COFs, which are apt at overcoming current challenges in COF design and open up new avenues to new real-world applications of COFs.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Polymer photocatalysts for solar-to-chemical energy conversion},

author = {T Banerjee and F Podjaski and J Kr\"{o}ger and B P Biswal and B V Lotsch},

url = {https://doi.org/10.1038/s41578-020-00254-z},

doi = {10.1038/s41578-020-00254-z},

issn = {2058-8437},

year  = {2020},

date = {2020-11-05},

journal = {Nature Reviews Materials},

abstract = {Solar-to-chemical energy conversion for the generation of high-energy chemicals is one of the most viable solutions to the quest for sustainable energy resources. Although long dominated by inorganic semiconductors, organic polymeric photocatalysts offer the advantage of a broad, molecular-level design space of their optoelectronic and surface catalytic properties, owing to their molecularly precise backbone. In this Review, we discuss the fundamental concepts of polymeric photocatalysis and examine different polymeric photocatalysts, including carbon nitrides, conjugated polymers, covalent triazine frameworks and covalent organic frameworks. We analyse the photophysical and physico-chemical concepts that govern the photocatalytic performance of these materials, and derive design principles and possible future research directions in this emerging field of ‘soft photocatalysis’.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Carbon nitride-based light-driven microswimmers with intrinsic photocharging ability},

author = {V Sridhar and F Podjaski and J Kr\"{o}ger and A Jim\'{e}nez-Solano and B-W Park and B V Lotsch and M Sitti},

url = {http://www.pnas.org/content/117/40/24748.abstract},

doi = {10.1073/pnas.2007362117},

year  = {2020},

date = {2020-09-21},

journal = {Proceedings of the National Academy of Sciences},

volume = {117},

number = {40},

pages = {24748},

abstract = {Light-driven microswimmers offer prospects for autonomous microsystems. Understanding their surface catalytic processes responsible for propulsion is essential in tailoring them for specific applications. So far, photocatalytic microswimmers have been limited by the requirement of continuous illumination. Here, we report light-driven 2D carbon nitride-based Janus microswimmers, which show efficient propulsion in aqueous media not only during but also after illumination for about 30 min after 30 s prior illumination, due to so-called solar battery swimming. Contrary to the mainstream reports, we reveal oxygen reduction rather than hydrogen evolution being responsible for propulsion with alcohol fuels. Balancing reaction conditions, we report the realization of light-induced intrinsic charging of a microswimmer, enabling sustained ballistic propulsion in the dark through discharge of accumulated energy.Controlling autonomous propulsion of microswimmers is essential for targeted drug delivery and applications of micro/nanomachines in environmental remediation and beyond. Herein, we report two-dimensional (2D) carbon nitride-based Janus particles as highly efficient, light-driven microswimmers in aqueous media. Due to the superior photocatalytic properties of poly(heptazine imide) (PHI), the microswimmers are activated by both visible and ultraviolet (UV) light in conjunction with different capping materials (Au, Pt, and SiO2) and fuels (H2O2 and alcohols). Assisted by photoelectrochemical analysis of the PHI surface photoreactions, we elucidate the dominantly diffusiophoretic propulsion mechanism and establish the oxygen reduction reaction (ORR) as the major surface reaction in ambient conditions on metal-capped PHI and even with TiO2-based systems, rather than the hydrogen evolution reaction (HER), which is generally invoked as the source of propulsion under ambient conditions with alcohols as fuels. Making use of the intrinsic solar energy storage ability of PHI, we establish the concept of photocapacitive Janus microswimmers that can be charged by solar energy, thus enabling persistent light-induced propulsion even in the absence of illumination\textemdasha process we call “solar battery swimming”\textemdashlasting half an hour and possibly beyond. We anticipate that this propulsion scheme significantly extends the capabilities in targeted cargo/drug delivery, environmental remediation, and other potential applications of micro/nanomachines, where the use of versatile earth-abundant materials is a key prerequisite.All data, materials, and associated protocols that support the findings of this study are shown in Materials and Methods and SI Appendix.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Ionothermal Synthesis of Imide-Linked Covalent Organic Frameworks},

author = {J Maschita and T Banerjee and G Savasci and F Haase and C Ochsenfeld and B V Lotsch},

url = {https://doi.org/10.1002/anie.202007372},

doi = {https://doi.org/10.1002/anie.202007372},

issn = {1433-7851},

year  = {2020},

date = {2020-09-01},

journal = {Angewandte Chemie International Edition},

volume = {59},

number = {36},

pages = {15750-15758},

abstract = {Abstract Covalent organic frameworks (COFs) are an extensively studied class of porous materials, which distinguish themselves from other porous polymers in their crystallinity and high degree of modularity, enabling a wide range of applications. COFs are most commonly synthesized solvothermally, which is often a time-consuming process and restricted to well-soluble precursor molecules. Synthesis of polyimide-linked COFs (PI-COFs) is further complicated by the poor reversibility of the ring-closing reaction under solvothermal conditions. Herein, we report the ionothermal synthesis of crystalline and porous PI-COFs in zinc chloride and eutectic salt mixtures. This synthesis does not require soluble precursors and the reaction time is significantly reduced as compared to standard solvothermal synthesis methods. In addition to applying the synthesis to previously reported imide COFs, a new perylene-based COF was also synthesized, which could not be obtained by the classical solvothermal route. In situ high-temperature XRPD analysis hints to the formation of precursor?salt adducts as crystalline intermediates, which then react with each other to form the COF.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Disorder and Linker Deficiency in Porphyrinic Zr-MOFs: Resolving the Zr8O6 Cluster Conundrum in PCN-221},

author = {C Koschnick and R St\"{a}glich and T Scholz and M Terban and A V Mankowski and G Savasci and F Binder and A Sch\"{o}kel and M Etter and J Nuss and R Siegel and L Germann and C Ochsenfeld and R Dinnebier and J Senker and B V Lotsch},

url = {http://europepmc.org/abstract/PPR/PPR210987 

https://doi.org/10.26434/chemrxiv.12918968.v1},

doi = {10.26434/chemrxiv.12918968.v1},

year  = {2020},

date = {2020-09-01},

urldate = {2020-09-01},

publisher = {ChemRxiv},

abstract = {Porphyrin-based metal-organic frameworks (MOFs), exemplified by the prototypical representatives MOF-525, PCN-221, and PCN-224 are among the most promising MOF systems for catalysis, optoelectronics, and solar energy conversion. However, subtle differences between synthetic protocols for these three MOFs give rise to vast discrepancies in purported product outcomes and description of framework topologies. Here, we reveal the type and disorder of the Zr-clusters based on a comprehensive synthetic and structural analysis spanning local and long-range length scales. Our analysis on PCN-221 reveals Zr6O4(OH)4 clusters in four distinct orientations within the unit cell, rather than Zr8O6 clusters as originally published, accompanied by random linker vacancies around 50%. We propose disordered PCN-224 (dPCN-224) as a unified model to understand PCN-221, MOF-525, and PCN-224 by varying the degree of orientational cluster disorder, linker conformation and vacancies, and cluster\textemdashlinker binding. Our work thus introduces a new perspective on network topology and disorder in Zr-MOFs and pinpoints the structural variables that direct their functional properties.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Near-atomic-scale observation of grain boundaries in a layer-stacked two-dimensional polymer},

author = {H Y Qi and H Sahabudeen and B K Liang and M Polozij and M A Addicoat and T E Gorelik and M Hambsch and M Mundszinger and S Park and B V Lotsch and S C B Mannsfeld and Z K Zheng and R H Dong and T Heine and X L Feng and U Kaiser},

url = {\<Go to ISI\>://WOS:000560465800030},

doi = {10.1126/sciadv.abb5976},

issn = {2375-2548},

year  = {2020},

date = {2020-08-14},

journal = {Science Advances},

volume = {6},

number = {33},

abstract = {Two-dimensional (2D) polymers, hold great promise in the rational materials design tailored for next-generation applications. However, little is known about the grain boundaries in 2D polymers, not to mention their formation mechanisms and potential influences on the material's functionalities. Using aberration-corrected high-resolution transmission electron microscopy, we present a direct observation of the grain boundaries in a layer-stacked 2D polyimine with a resolution of 2.3 angstrom, shedding light on their formation mechanisms. We found that the polyimine growth followed a "birth-and-spread" mechanism. Antiphase boundaries implemented a self-correction to the missing-linker and missing-node defects, and tilt boundaries were formed via grain coalescence. Notably, we identified grain boundary reconstructions featuring closed rings at tilt boundaries. Quantum mechanical calculations revealed that boundary reconstruction is energetically allowed and can be generalized into different 2D polymer systems. We envisage that these results may open up the opportunity for future investigations on defect-property correlations in 2D polymers.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Toward Standardized Photocatalytic Oxygen Evolution Rates Using RuO2@TiO2 as a Benchmark},

author = {H A Vignolo-Gonz\'{a}lez and S Laha and A Jim\'{e}nez-Solano and T Oshima and V Duppel and P Sch\"{u}tzend\"{u}be and B V Lotsch},

url = {http://www.sciencedirect.com/science/article/pii/S2590238520303799},

doi = {https://doi.org/10.1016/j.matt.2020.07.021},

issn = {2590-2385},

year  = {2020},

date = {2020-08-05},

journal = {Matter},

volume = {3},

number = {2},

pages = {464-486},

abstract = {Summary Quantitative comparison of photocatalytic performances across different photocatalysis setups is technically challenging. Here, we combine the concepts of relative and optimal photonic efficiencies to normalize activities with an internal benchmark material, RuO2 photodeposited on a P25-TiO2 photocatalyst, which was optimized for reproducibility of the oxygen evolution reaction (OER). Additionally, a general set of good practices was identified to ensure reliable quantification of photocatalytic OER, including photoreactor design, photocatalyst dispersion, and control of parasitic reactions caused by the sacrificial electron acceptor. Moreover, a method combining optical modeling and measurements was proposed to quantify the benchmark absorbed and scattered light (7.6% and 81.2%, respectively, of λ = 300\textendash500 nm incident photons), rather than just incident light (≈AM 1.5G), to estimate its internal quantum efficiency (16%). We advocate the adoption of the instrumental and theoretical framework provided here to facilitate material standardization and comparison in the field of artificial photosynthesis.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Rational Design of Covalent Cobaloxime-Covalent Organic Framework Hybrids for Enhanced Photocatalytic Hydrogen Evolution},

author = {K Gottschling and G Savasci and H Vignolo-Gonzalez and S Schmidt and P Mauker and T Banerjee and P Rovo and C Ochsenfeld and B V Lotsch},

url = {\<Go to ISI\>://WOS:000551495700030},

doi = {10.1021/jacs.0c02155},

issn = {0002-7863},

year  = {2020},

date = {2020-07-15},

journal = {Journal of the American Chemical Society},

volume = {142},

number = {28},

pages = {12146-12156},

abstract = {Covalent organic frameworks (COFs) display a unique combination of chemical tunability, structural diversity, high porosity, nanoscale regularity, and thermal stability. Recent efforts are directed at using such frameworks as tunable scaffolds for chemical reactions. In particular, COFs have emerged as viable platforms for mimicking natural photosynthesis. However, there is an indisputable need for efficient, stable, and economical alternatives for the traditional platinum-based cocatalysts for light-driven hydrogen evolution. Here, we present azide-functionalized chloro(pyridine)cobaloxime hydrogen-evolution cocatalysts immobilized on a hydrazone-based COF-42 backbone that show improved and prolonged photocatalytic activity with respect to equivalent physisorbed systems. Advanced solid-state NMR and quantum-chemical methods allow us to elucidate details of the improved photoreactivity and the structural composition of the involved active site. We found that a genuine interaction between the COF backbone and the cobaloxime facilitates recoordination of the cocatalyst during the photoreaction, thereby improving the reactivity and hindering degradation of the catalyst. The excellent stability and prolonged reactivity make the herein reported cobaloxime-tethered COF materials promising hydrogen evolution catalysts for future solar fuel technologies.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Total scattering reveals the hidden stacking disorder in a 2D covalent organic framework},

author = {A M P\"{u}tz and M W Terban and S Bette and F Haase and R E Dinnebier and B V Lotsch},

url = {http://dx.doi.org/10.1039/D0SC03048A},

doi = {10.1039/D0SC03048A},

issn = {2041-6520},

year  = {2020},

date = {2020-07-08},

journal = {Chemical Science},

abstract = {Interactions between extended π-systems are often invoked as the main driving force for stacking and crystallization of 2D organic polymers. In covalent organic frameworks (COFs), the stacking strongly influences properties such as the accessibility of functional sites, pore geometry, and surface states, but the exact nature of the interlayer interactions is mostly elusive. The stacking mode is often identified as eclipsed based on observed high symmetry diffraction patterns. However, as pointed out by various studies, the energetics of eclipsed stacking are not favorable and offset stacking is preferred. This work presents lower and higher apparent symmetry modifications of the imine-linked TTI-COF prepared through high- and low-temperature reactions. Through local structure investigation by pair distribution function analysis and simulations of stacking disorder, we observe random local layer offsets in the low temperature modification. We show that while stacking disorder can be easily overlooked due to the apparent crystallographic symmetry of these materials, total scattering methods can help clarify this information and suggest that defective local structures could be much more prevalent in COFs than previously thought. A detailed analysis of the local structure helps to improve the search for and design of highly porous tailor-made materials.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Enhancing Hydrogen Evolution Activity of Au(111) in Alkaline Media through Molecular Engineering of a 2D Polymer},

author = {P Alexa and J M Lombardi and P Abufager and H F Busnengo and D Grumelli and V S Vyas and F Haase and B V Lotsch and R Gutzler and K Kern},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/anie.201915855},

doi = {10.1002/anie.201915855},

issn = {1433-7851},

year  = {2020},

date = {2020-05-05},

journal = {Angewandte Chemie International Edition},

volume = {n/a},

number = {n/a},

abstract = {Abstract The electrochemical splitting of water holds promise for the storage of energy produced intermittently by renewable energy sources. The evolution of hydrogen currently relies on the use of platinum as a catalyst\textemdashwhich is scarce and expensive\textemdashand ongoing research is focused towards finding cheaper alternatives. In this context, 2D polymers grown as single layers on surfaces have emerged as porous materials with tunable chemical and electronic structures that can be used for improving the catalytic activity of metal surfaces. Here, we use designed organic molecules to fabricate covalent 2D architectures by an Ullmann-type coupling reaction on Au(111). The polymer-patterned gold electrode exhibits a hydrogen evolution reaction activity up to three times higher than that of bare gold. Through rational design of the polymer on the molecular level we engineered hydrogen evolution activity by an approach that can be easily extended to other electrocatalytic reactions.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Holey Heterographenes Made to Order: “Green” Synthesis of Porous Graphitic Frameworks},

author = {T Banerjee and B V Lotsch},

url = {https://www.sciencedirect.com/science/article/pii/S245192942030125X},

doi = {https://doi.org/10.1016/j.chempr.2020.03.012},

issn = {2451-9294},

year  = {2020},

date = {2020-04-09},

journal = {Chem},

volume = {6},

number = {4},

pages = {812-814},

abstract = {Fully annulated pyrazine-linked porous graphitic frameworks (PGFs) have garnered attention because of their potential applications in optoelectronics and energy storage. In this issue of Chem, Zhang, Liu, and co-workers report a base-promoted aqueous synthesis of such porous heterographenes with high crystallinity and application potential as cathodes in lithium-ion batteries.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {How Certain Are the Reported Ionic Conductivities of Thiophosphate-Based Solid Electrolytes? An Interlaboratory Study},

author = {S Ohno and T Bernges and J Buchheim and M Duchardt and A-K Hatz and M A Kraft and H Kwak and A L Santhosha and Z Liu and N Minafra and F Tsuji and A Sakuda and R Schlem and S Xiong and Z Zhang and P Adelhelm and H Chen and A Hayashi and Y S Jung and B V Lotsch and B Roling and N M Vargas-Barbosa and W G Zeier},

url = {https://doi.org/10.1021/acsenergylett.9b02764},

doi = {10.1021/acsenergylett.9b02764},

year  = {2020},

date = {2020-03-13},

journal = {ACS Energy Letters},

volume = {5},

number = {3},

pages = {910-915},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Finding the Right Blend: Interplay Between Structure and Sodium Ion Conductivity in the System Na5AlS4\textendashNa4SiS4},

author = {S Harm and A-K Hatz and C Schneider and C Hoefer and C Hoch and B V Lotsch},

url = {https://www.frontiersin.org/article/10.3389/fchem.2020.00090},

doi = {10.3389/fchem.2020.00090},

issn = {2296-2646},

year  = {2020},

date = {2020-02-18},

journal = {Frontiers in Chemistry},

volume = {8},

pages = {90},

abstract = {The rational design of high performance sodium solid electrolytes is one of the key challenges in modern battery research. In this work, we identify new sodium ion conductors in the substitution series Na_{5-x}Al_{1-x}Si_{x}S4 (0 ≤ x ≤ 1), which are entirely based on earth-abundant elements. These compounds exhibit conductivities ranging from 1.64 · 10^{−7} for Na_{4}SiS_{4} to 2.04 · 10^{−5} for Na_{8.5}(AlS_{4})_{0.5}(SiS_{4})_{1.5} (x = 0.75). We determined the crystal structures of the Na^{+}-ion conductors Na_{4}SiS_{4} as well as hitherto unknown Na_{5}AlS_{4} and Na_{9}(AlS_{4})(SiS_{4}). Na^{+}-ion conduction pathways were calculated by bond valence energy landscape (BVEL) calculations for all new structures highlighting the influence of the local coordination symmetry of sodium ions on the energy landscape within this family. Our findings show that the interplay of charge carrier concentration and low site symmetry of sodium ions can enhance the conductivity by several orders of magnitude.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Lanthanide orthothiophosphates revisited: single-crystal X-ray, Raman, and DFT studies of TmPS4 and YbPS4},

author = {T Scholz and F Pielnhofer and R Eger and B V Lotsch},

doi = {10.1515/znb-2019-0217},

year  = {2020},

date = {2020-01-28},

journal = {Zeitschrift f\"{u}r Naturforschung B},

volume = {75},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Customizing H3Sb3P2O14 nanosheet sensors by reversible vapor-phase amine intercalation},

author = {M D\"{a}ntl and P Ganter and K Szendrei-Temesi and A Jim\'{e}nez-Solano and B V Lotsch},

url = {http://dx.doi.org/10.1039/C9NH00434C},

doi = {10.1039/C9NH00434C},

issn = {2055-6756},

year  = {2020},

date = {2020-01-01},

journal = {Nanoscale Horizons},

volume = {5},

number = {1},

pages = {74-81},

abstract = {Harvesting the large property space of 2D materials and their molecular-level fine-tuning is of utmost importance for future applications such as miniaturized sensors for environmental monitoring or biomedical detection. Therefore, developing straightforward strategies for the reversible and gradual fine-tuning of nanosheet properties with soft chemical intercalation methods is in high demand. Herein we address this challenge by customizing the host\textendashguest interactions of nanosheets based on the solid acid H3Sb3P2O14 by vapor-phase amine-intercalation with primary alkylamines. Fine-tuning of the structural and chemical properties of the intercalated nanosheets is achieved by applying a two-step, post-synthetic intercalation strategy via the vapor phase. The method allows for the gradual and reversible replacement of one amine type by another. Hence, fine-tuning of the d-spacing in the sub-r{A} regime is accomplished and offers exquisite control of the properties of the thin films such as refractive index, polarity, film thickness and sensitivity towards solvent vapors. Moreover, we employ amine replacement to pattern thin films by locally resolved amine intercalation and subsequent washing, leading to spatially dependent property profiles. This process thus adds a new vapor-phase, amine-based variant to the toolbox of soft lithography.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Rational strain engineering in delafossite oxides for highly efficient hydrogen evolution catalysis in acidic media},

author = {F Podjaski and D Weber and S Zhang and L Diehl and R Eger and V Duppel and E Alarc\'{o}n-Llad\'{o} and G Richter and F Haase and A Fontcuberta I Morral and C Scheu and B V Lotsch},

url = {https://doi.org/10.1038/s41929-019-0400-x},

doi = {10.1038/s41929-019-0400-x},

issn = {2520-1158},

year  = {2020},

date = {2020-01-01},

journal = {Nature Catalysis},

volume = {3},

number = {1},

pages = {55-63},

abstract = {The rational design of hydrogen evolution reaction electrocatalysts that can compete with platinum is an outstanding challenge in the process of designing viable power-to-gas technologies. Here, we introduce delafossites as a family of hydrogen evolution reaction electrocatalysts in acidic media. We show that, in PdCoO2, the inherently strained Pd metal sublattice acts as a pseudomorphic template for the growth of a tensile-strained Pd-rich capping layer under reductive conditions. The surface modification ranges up to 400 nm and continuously improves the electrocatalytic activity by simultaneously increasing the exchange current density and by reducing the Tafel slope down to 38 mV dec−1, leading to overpotentials η10 \< 15 mV. The improved activity is attributed to the operando stabilization of a β-PdHx phase with enhanced surface catalytic properties with respect to pure or nanostructured palladium. These findings illustrate how operando-induced electrodissolution can be used as a top-down design concept through the strain-stabilized formation of catalytically active phases.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Rational strain engineering in delafossite oxides for highly efficient hydrogen evolution catalysis in acidic media},

author = {F Podjaski and D Weber and S Zhang and L Diehl and R Eger and V Duppel and E Alarc\'{o}n-Llad\'{o} and G Richter and F Haase and A Fontcuberta I Morral and C Scheu and B V Lotsch},

url = {https://doi.org/10.1038/s41929-019-0400-x},

doi = {10.1038/s41929-019-0400-x},

issn = {2520-1158},

year  = {2020},

date = {2020-01-01},

journal = {Nature Catalysis},

volume = {3},

number = {1},

pages = {55-63},

abstract = {The rational design of hydrogen evolution reaction electrocatalysts that can compete with platinum is an outstanding challenge in the process of designing viable power-to-gas technologies. Here, we introduce delafossites as a family of hydrogen evolution reaction electrocatalysts in acidic media. We show that, in PdCoO2, the inherently strained Pd metal sublattice acts as a pseudomorphic template for the growth of a tensile-strained Pd-rich capping layer under reductive conditions. The surface modification ranges up to 400 nm and continuously improves the electrocatalytic activity by simultaneously increasing the exchange current density and by reducing the Tafel slope down to 38 mV dec−1, leading to overpotentials η10 \< 15 mV. The improved activity is attributed to the operando stabilization of a β-PdHx phase with enhanced surface catalytic properties with respect to pure or nanostructured palladium. These findings illustrate how operando-induced electrodissolution can be used as a top-down design concept through the strain-stabilized formation of catalytically active phases.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Synthesis and Structure of the Sodium Phosphidosilicate Na2SiP2},

author = {A Haffner and A K Hatz and C Hoch and B V Lotsch and D Johrendt},

url = {\<Go to ISI\>://WOS:000511390500001},

doi = {10.1002/ejic.201901083},

issn = {1434-1948},

year  = {2019},

date = {2019-12-29},

journal = {European Journal of Inorganic Chemistry},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Change in Magnetic Properties upon Chemical Exfoliation of FeOCl},

author = {A M Ferrenti and S Klemenz and S M Lei and X Y Song and P Ganter and B V Lotsch and L M Schoop},

url = {\<Go to ISI\>://WOS:000509420100027},

doi = {10.1021/acs.inorgchem.9b02856},

issn = {0020-1669},

year  = {2019},

date = {2019-12-27},

journal = {Inorganic Chemistry},

volume = {59},

number = {2},

pages = {1176-1182},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Structural Evolution of Ni-Based Co-Catalysts on [Ca2Nb3O10]− Nanosheets during Heating and Their Photocatalytic Properties},

author = {S Zhang and L Diehl and S Wrede and B V Lotsch and C Scheu},

url = {https://www.mdpi.com/2073-4344/10/1/13},

issn = {2073-4344},

year  = {2019},

date = {2019-12-20},

journal = {Catalysts},

volume = {10},

number = {1},

pages = {13},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Rational strain engineering in delafossite oxides for highly efficient hydrogen evolution catalysis in acidic media},

author = {F Podjaski and D Weber and S Zhang and L Diehl and R Eger and V Duppel and Alarcon E Llado and G Richter and F Haase and A Fontcuberta I Morral and C Scheu and B V Lotsch},

doi = {10.1038/s41929-019-0400-x},

year  = {2019},

date = {2019-12-01},

journal = {Nature Catalysis},

volume = {3},

pages = {1-9},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Structural Insights into Poly(Heptazine Imides): A Light Storing Carbon Nitride Material for Dark Photocatalysis},

author = {H Schlomberg and J Kr\"{o}ger and G Savasci and M Terban and S Bette and I Moudrakovski and V Duppel and F Podjaski and R Siegel and J Senker and R Dinnebier and C Ochsenfeld and B V Lotsch},

doi = {10.1021/acs.chemmater.9b02199},

year  = {2019},

date = {2019-08-12},

journal = {Chemistry of Materials},

volume = {31},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Sustained Solar H-2 Evolution from a Thiazolo 5,4-d thiazole-Bridged Covalent Organic Framework and Nickel-Thiolate Cluster in Water},

author = {B P Biswal and H A Vignolo-Gonzalez and T Banerjee and L Grunenberg and G Savasci and K Gottschling and J Nuss and C Ochsenfeld and B V Lotsch},

url = {\<Go to ISI\>://WOS:000476684700023},

doi = {10.1021/jacs.9b03243},

issn = {0002-7863},

year  = {2019},

date = {2019-06-20},

journal = {Journal of the American Chemical Society},

volume = {141},

number = {28},

pages = {11082-11092},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Sub-stoichiometric 2D covalent organic frameworks from tri- and tetratopic linkers},

author = {T Banerjee and F Haase and S Trenker and B P Biswal and G Savasci and V Duppel and I Moudrakovski and C Ochsenfeld and B V Lotsch},

url = {\<Go to ISI\>://WOS:000472032300004},

doi = {10.1038/s41467-019-10574-6},

issn = {2041-1723},

year  = {2019},

date = {2019-06-19},

journal = {Nature Communications},

volume = {10},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Short-Range Structural Correlations in Amorphous 2D Polymers},

author = {P Alexa and C Oligschleger and P Gr\"{o}ger and C Morchutt and V Vyas and B V Lotsch and J C Sch\"{o}n and R Gutzler and K Kern},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/cphc.201900326},

doi = {10.1002/cphc.201900326},

issn = {1439-4235},

year  = {2019},

date = {2019-05-21},

journal = {ChemPhysChem},

volume = {20},

number = {18},

pages = {2340-2347},

abstract = {Abstract Many 2D covalent polymers synthesized as single layers on surfaces show inherent disorder, expressed for example in their ring-size distribution. Systems which are expected to form the thermodynamically favored hexagonal lattice usually deviate from crystallinity and include high numbers of pentagons, heptagons, and rings of other sizes. The amorphous structure of two different covalent polymers in real space using scanning tunneling microscopy is investigated. Molecular dynamics simulations are employed to extract additional information. We show that short-range correlations exist in the structure of one polymer, i. e. that polygons are not tessellating the surface randomly but that ring neighborhoods have preferential compositions. The correlation is dictated by the energy of formation of the ring neighborhoods.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Ruthenium Oxide Nanosheets for Enhanced Oxygen Evolution Catalysis in Acidic Medium},

author = {S Laha and Y Lee and F Podjaski and D Weber and V Duppel and L M Schoop and F Pielnhofer and C Scheurer and K Muller and U Starke and K Reuter and B V Lotsch},

url = {\<Go to ISI\>://WOS:000465464500007},

doi = {10.1002/aenm.201803795},

issn = {1614-6832},

year  = {2019},

date = {2019-02-21},

journal = {Advanced Energy Materials},

volume = {9},

number = {15},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {A new ultrafast superionic Li-conductor: ion dynamics in Li11Si2PS12 and comparison with other tetragonal LGPS-type electrolytes},

author = {A Kuhn and O Gerbig and C Zhu and F Falkenberg and J Maier and B V Lotsch},

url = {http://dx.doi.org/10.1039/C4CP02046D},

doi = {10.1039/C4CP02046D},

issn = {1463-9076},

year  = {2014},

date = {2014-05-23},

journal = {Physical Chemistry Chemical Physics},

volume = {16},

number = {28},

pages = {14669-14674},

abstract = {We report on a new ultrafast solid electrolyte of the composition Li11Si2PS12, which exhibits a higher room-temperature Li ion diffusivity than the present record holder Li10GeP2S12. We discuss the high-pressure synthesis and ion dynamics of tetragonal Li11Si2PS12, and comparison is made with our investigations of related members of the LMePS family, i.e. electrolytes of the general formula Li11−xMe2−xP1+xS12 with Me = Ge, Sn : Li10GeP2S12, Li7GePS8, Li10SnP2S12. The structure and dynamics were studied with multiple complementary techniques and the macroscopic diffusion could be traced back to fast Li ion hopping in the crystalline lattice. A clear correlation between the diffusivity and the unit cell volume of the LGPS-type electrolytes was observed.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}