Publications

@article{nokey,

title = {Ionic liquids tailoring crystal orientation and electronic properties for stable perovskite solar cells},

author = {Y Zou and J Eichhorn and S Rieger and Y Zheng and S Yuan and L Wolz and L V Spanier and J E Heger and S Yin and C R Everett and L Dai and M Schwartzkopf and C Mu and S V Roth and I D Sharp and C-C Chen and J Feldmann and S D Stranks and P M\"{u}ller-Buschbaum},

url = {https://www.sciencedirect.com/science/article/pii/S2211285523002860},

doi = {https://doi.org/10.1016/j.nanoen.2023.108449},

issn = {2211-2855},

year  = {2023},

date = {2023-04-21},

journal = {Nano Energy},

volume = {112},

pages = {108449},

abstract = {The crystallization behavior of perovskite films has a profound influence on the resulting defect densities, charge carrier dynamics and photovoltaic performance. Herein, we introduce ionic liquids into the perovskite component to tailor the crystal growth of perovskite films from a disordered to a preferential corner-up orientation and accordingly increase the charge carrier mobility to accelerate electron transport and extraction. Using time-resolved measurements, we probe the charge carrier generation, transport and recombination behavior in these films and related devices. We find the ionic liquid-containing samples exhibit lower defects, faster charge carrier transport and suppressed non-radiative recombination, contributing to higher efficiency and fill factor. Via operando grazing-incidence small- and wide-angle X-ray scattering measurements, we observe a light-induced lattice compression and grain fragmentation in the control devices, whereas the ionic liquid-containing devices exhibit a slight light-induced crystal reconstitution and stronger tolerance against illumination. Under ambient conditions, the non-encapsulated device with the pyrrolidinium-based ionic compound (Pyr14BF4) maintains 97% of its initial efficiency after 4368 h.},

keywords = {Foundry Inorganic, Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Formation of active sites on transition metals through reaction-driven migration of surface atoms},

author = {L Xu and K G Papanikolaou and B A J Lechner and L Je and G A Somorjai and M Salmeron and M Mavrikakis},

url = {https://www.science.org/doi/abs/10.1126/science.add0089},

doi = {doi:10.1126/science.add0089},

year  = {2023},

date = {2023-04-06},

urldate = {2023-04-06},

journal = {Science},

volume = {380},

number = {6640},

pages = {70-76},

abstract = {Adopting low-index single-crystal surfaces as models for metal nanoparticle catalysts has been questioned by the experimental findings of adsorbate-induced formation of subnanometer clusters on several single-crystal surfaces. We used density functional theory calculations to elucidate the conditions that lead to cluster formation and show how adatom formation energies enable efficient screening of the conditions required for adsorbate-induced cluster formation. We studied a combination of eight face-centered cubic transition metals and 18 common surface intermediates and identified systems relevant to catalytic reactions, such as carbon monoxide (CO) oxidation and ammonia (NH3) oxidation. We used kinetic Monte Carlo simulations to elucidate the CO-induced cluster formation process on a copper surface. Scanning tunneling microscopy of CO on a nickel (111) surface that contains steps and dislocations points to the structure sensitivity of this phenomenon. Metal-metal bond breaking that leads to the evolution of catalyst structures under realistic reaction conditions occurs much more broadly than previously thought. In heterogeneous catalysis, it is often assumed that adsorbates have minimal effects on the bonding between surface metal atoms at low temperatures and pressures. Xu et al. used density functional theory to find conditions in which adsorbed molecules can scavenge transition metal atoms by breaking bonds at the surface. These atoms can then form clusters, as observed in kinetic Monte Carlo simulations of carbon monoxide on copper and in scanning tunneling microscopy studies of carbon monoxide on a Ni(111) surface containing steps and dislocations. The reaction mechanisms of several catalytic systems may be dominated by in situ adsorbate-induced active site formation. \textemdashPDS Metal atoms freed from transition metal surfaces during reaction can then form clusters that are catalytically active.},

keywords = {Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Elucidating the Roles of Nafion/Solvent Formulations in Copper-Catalyzed CO2 Electrolysis},

author = {P Ding and H An and P Zellner and T Guan and J Gao and P M\"{u}ller-Buschbaum and B M Weckhuysen and W Van Der Stam and I D Sharp},

url = {https://doi.org/10.1021/acscatal.2c05235},

doi = {10.1021/acscatal.2c05235},

year  = {2023},

date = {2023-04-05},

journal = {ACS Catalysis},

pages = {5336-5347},

abstract = {Nafion ionomer, composed of hydrophobic perfluorocarbon backbones and hydrophilic sulfonic acid side chains, is the most widely used additive for preparing catalyst layers (CLs) for electrochemical CO2 reduction, but its impact on the performance of CO2 electrolysis remains poorly understood. Here, we systematically investigate the role of the catalyst ink formulation on CO2 electrolysis using commercial CuO nanoparticles as the model pre-catalyst. We find that the presence of Nafion is essential for achieving stable product distributions due to its ability to stabilize the catalyst morphology under reaction conditions. Moreover, the Nafion content and solvent composition (water/alcohol fraction) regulate the internal structure of Nafion coatings, as well as the catalyst morphology, thereby significantly impacting CO2 electrolysis performance, resulting in variations of C2+ product Faradaic efficiency (FE) by \>3×, with C2+ FE ranging from 17 to 54% on carbon paper substrates. Using a combination of ellipsometry and in situ Raman spectroscopy during CO2 reduction, we find that such selectivity differences stem from changes to the local reaction microenvironment. In particular, the combination of high water/alcohol ratios and low Nafion fractions in the catalyst ink results in stable and favorable microenvironments, increasing the local CO2/H2O concentration ratio and promoting high CO surface coverage to facilitate C2+ production in long-term CO2 electrolysis. Therefore, this work provides insights into the critical role of Nafion binders and underlines the importance of optimizing Nafion/solvent formulations as a means of enhancing the performance of electrochemical CO2 reduction systems.},

keywords = {Foundry Inorganic, Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Electron Tunneling at Electrocatalytic Interfaces},

author = {M R Nouri and R M Kluge and R W Haid and J Fortmann and A Ludwig and A S Bandarenka and V Alexandrov},

url = {https://doi.org/10.1021/acs.jpcc.3c00207},

doi = {10.1021/acs.jpcc.3c00207},

issn = {1932-7447},

year  = {2023},

date = {2023-03-27},

journal = {The Journal of Physical Chemistry C},

volume = {127},

number = {13},

pages = {6321-6327},

abstract = {It was recently proposed that tunneling current fluctuations in electrochemical scanning tunneling microscopy (EC-STM) can be used to map the electrocatalytic activity of surfaces with high spatial resolution. However, the relation between the increased noise in the electron tunneling signal and the local reactivity for such complex electrode/electrolyte interfaces is only explained qualitatively or hypothetically. Herein, we employ electron transport calculations to examine tunneling at Pt surfaces under the conditions of the oxygen reduction reaction as a case study. By computing current\textendashvoltage characteristics, we reveal that the tunneling barrier strongly depends on the chemical identity of the adsorbed reaction intermediate as well as on the orientation of the average dipole moment of water species mediating electron tunneling. Our theoretical results combined with EC-STM measurements suggest that detecting reaction intermediates at electrified interfaces in operando conditions is possible based on tunneling noise amplitudes. This study also aims to stimulate further explorations of tunneling-based electron-proton transfers to enable quantum electrocatalysis beyond conventional approaches.},

keywords = {Foundry Inorganic, Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Transient absorption spectroscopy based on uncompressed hollow core fiber white light proves pre-association between a radical ion photocatalyst and substrate},

author = {A Kumar and P Malevich and L Mewes and S Wu and J P Barham and J Hauer},

url = {https://aip.scitation.org/doi/abs/10.1063/5.0142225},

doi = {10.1063/5.0142225},

year  = {2023},

date = {2023-03-24},

journal = {The Journal of Chemical Physics},

volume = {158},

number = {14},

pages = {144201},

abstract = {We present a hollow-core fiber (HCF) based transient absorption experiment, with capabilities beyond common titanium:sapphire based setups. By spectral filtering of the HCF spectrum, we provide pump pulses centered at 425 nm with several hundred nJ of pulse energy at the sample position. By employing the red edge of the HCF output for seeding CaF2, we obtain smooth probing spectra in the range between 320 and 900 nm. We demonstrate the capabilities of our experiment by following the ultrafast relaxation dynamics of a radical cationic photocatalyst to prove its pre-association with an arene substrate, a phenomenon that was not detectable previously by steady-state spectroscopic techniques. The detected preassembly rationalizes the successful participation of radical ionic photocatalysts in single electron transfer reactions, a notion that has been subject to controversy in recent years.},

keywords = {Molecularly-Functionalized, Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {A re-useable microreactor for dynamic and sensitive photocatalytic measurements: Exemplified by the photoconversion of ethanol on Pt-loaded titania P25},

author = {C C Aletsee and D Hochfilzer and A Kwiatkowski and M Becherer and J Kibsgaard and I Chorkendorff and M Tschurl and U Heiz},

url = {https://aip.scitation.org/doi/abs/10.1063/5.0134287},

doi = {10.1063/5.0134287},

year  = {2023},

date = {2023-03-23},

journal = {Review of Scientific Instruments},

volume = {94},

number = {3},

pages = {033909},

abstract = {Despite numerous advancements in synthesizing photoactive materials, the evaluation of their catalytic performance remains challenging since their fabrication often involves tedious strategies, yielding only low quantities in the μ-gram scale. In addition, these model catalysts exhibit different forms, such as powders or film(-like) structures grown on various supporting materials. Herein, we present a versatile gas phase μ-photoreactor, compatible with different catalyst morphologies, which is, in contrast to existing systems, re-openable and \textendashuseable, allowing not only post-characterization of the photocatalytic material but also enabling catalyst screening studies in short experimental time intervals. Sensitive and time-resolved reaction monitoring at ambient pressure is realized by a lid-integrated capillary, transmitting the entire gas flow from the reactor chamber to a quadrupole mass spectrometer. Due to the microfabrication of the lid from borosilicate as base material, 88% of the geometrical area can be illuminated by a light source, further enhancing sensitivity. Gas dependent flow rates through the capillary were experimentally determined to be 1015\textendash1016 molecules s−1, and in combination with a reactor volume of 10.5 μl, this results in residence times below 40 s. Furthermore, the reactor volume can easily be altered by adjusting the height of the polymeric sealing material. The successful operation of the reactor is demonstrated by selective ethanol oxidation over Pt-loaded TiO2 (P25), which serves to exemplify product analysis from dark-illumination difference spectra.},

keywords = {Foundry Inorganic, Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Solution-processed NiPS3 thin films from Liquid Exfoliated Inks with Long-Lived Spin-Entangled Excitons},

author = {A Shcherbakov and K Synnatschke and S Bodnar and J Zerhoch and L Eyre and F Rauh and M W Heindl and S Liu and J Konecny and I D Sharp},

url = {https://arxiv.org/abs/2303.11788},

doi = {https://doi.org/10.48550/arXiv.2303.11788},

year  = {2023},

date = {2023-03-21},

journal = {arXiv preprint arXiv:2303.11788},

abstract = {Antiferromagnets are promising materials for future opto-spintronic applications since they show spin dynamics in the THz range and no net magnetization. Recently, layered van der Waals (vdW) antiferromagnets have been reported, which combine low-dimensional excitonic properties with complex spin-structure. While various methods for the fabrication of vdW 2D crystals exist, formation of large area and continuous thin films is challenging because of either limited scalability, synthetic complexity, or low opto-spintronic quality of the final material. Here, we fabricate centimeter-scale thin films of the van der Waals 2D antiferromagnetic material NiPS3, which we prepare using a crystal ink made from liquid phase exfoliation (LPE). We perform statistical atomic force microscopy (AFM) and scanning electron microscopy (SEM) to characterize and control the lateral size and number of layers through this ink-based fabrication. Using ultrafast optical spectroscopy at cryogenic temperatures, we resolve the dynamics of photoexcited excitons. We find antiferromagnetic spin arrangement and spin-entangled Zhang-Rice multiplet excitons with lifetimes in the nanosecond range, as well as ultranarrow emission linewidths, despite the disordered nature of our films. Thus, our findings demonstrate scalable thin-film fabrication of high-quality NiPS3, which is crucial for translating this 2D antiferromagnetic material into spintronic and nanoscale memory devices and further exploring its complex spin-light coupled states.},

keywords = {Foundry Inorganic, Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Improved In Situ Characterization of Electrochemical Interfaces Using Metasurface-Driven Surface-Enhanced IR Absorption Spectroscopy},

author = {L M Berger and M Duportal and L D S Menezes and E Cort\'{e}s and S A Maier and A Tittl and K Krischer},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/adfm.202300411},

doi = {https://doi.org/10.1002/adfm.202300411},

issn = {1616-301X},

year  = {2023},

date = {2023-03-20},

journal = {Advanced Functional Materials},

volume = {n/a},

number = {n/a},

pages = {2300411},

abstract = {Abstract Electrocatalysis plays a crucial role in realizing the transition toward a zero-carbon future, driving research directions from green hydrogen generation to carbon dioxide reduction. Surface-enhanced infrared absorption spectroscopy (SEIRAS) is a suitable method for investigating electrocatalytic processes because it can monitor with chemical specificity the mechanisms of the reactions. However, it remains difficult to detect many relevant aspects of electrochemical reactions such as short-lived intermediates. Herein, an integrated nanophotonic-electrochemical SEIRAS platform is developed and experimentally realized for the in situ investigation of molecular signal traces emerging during electrochemical experiments. A platinum nano-slot metasurface featuring strongly enhanced electromagnetic near fields is implemented and spectrally targets the weak vibrational mode of the adsorbed carbon monoxide at ≈2033 cm−1. The metasurface-driven resonances can be tuned over a broad range in the mid-infrared spectrum and provide high molecular sensitivity. Compared to conventional unstructured platinum films, this nanophotonic-electrochemical platform delivers a 27-fold improvement of the experimentally detected characteristic absorption signals, enabling the detection of new species with weak signals, fast conversions, or low surface concentrations. By providing a deeper understanding of catalytic reactions, the nanophotonic-electrochemical platform is anticipated to open exciting perspectives for electrochemical SEIRAS, surface-enhanced Raman spectroscopy, and other fields of chemistry such as photoelectrocatalysis.},

keywords = {Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Interpreting Ultrafast Electron Transfer on Surfaces with a Converged First-Principles Newns-Anderson Chemisorption Function},

author = {S Ghan and E Diesen and C Kunkel and K Reuter and H Oberhofer},

url = {https://arxiv.org/abs/2303.11412},

doi = {https://doi.org/10.48550/arXiv.2303.11412},

year  = {2023},

date = {2023-03-20},

journal = {arXiv preprint arXiv:2303.11412},

abstract = {We study the electronic coupling between an adsorbate and a metal surface by calculating tunneling matrix elements Had directly from first principles. For this we employ a projection of the Kohn-Sham Hamiltonian upon a diabatic basis using a version of the popular Projection-Operator Diabatization approach. An appropriate integration of couplings over the Brillouin zone allows the first calculation of a size-convergent Newns-Anderson chemisorption function, a coupling-weighted density of states measuring the line broadening of an adsorbate frontier state upon adsorption. This broadening corresponds to the experimentally-observed lifetime of an electron in the state, which we confirm for core-excited Ar∗(2p−13/24s) atoms on a number of transition metal (TM) surfaces. Yet, beyond just lifetimes, the chemisorption function is highly interpretable and encodes rich information on orbital phase interactions on the surface. The model thus captures and elucidates key aspects of the electron transfer process. Finally, a decomposition into angular momentum components reveals the hitherto unresolved role of the hybridized d-character of the TM surface in the resonant electron transfer, and elucidates the coupling of the adsorbate to the surface bands over the entire energy scale.},

keywords = {Foundry Inorganic, Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Imaging local diffusion in microstructures using NV-based pulsed field gradient NMR},

author = {R Allert and N Neuling and K Briegel},

url = {https://arxiv.org/abs/2303.03516},

doi = {https://doi.org/10.48550/arXiv.2303.03516},

year  = {2023},

date = {2023-03-06},

journal = {arXiv preprint arXiv:2303.03516},

abstract = {Understanding diffusion in microstructures plays a crucial role in many scientific fields, including neuroscience, cancer- or energy research. While magnetic resonance methods are the gold standard for quantitative diffusion measurements, they lack sensitivity in resolving and measuring diffusion within individual microstructures. Here, we introduce nitrogen-vacancy (NV) center based nuclear magnetic resonance (NMR) spectroscopy as a novel tool to probe diffusion in individual structures on microscopic length scales. We have developed a novel experimental scheme combining pulsed gradient spin echo (PGSE) with optically detected NV-NMR, which allows for the quantification of molecular diffusion and flow within nano-to-picoliter sample volumes. We demonstrate correlated optical imaging with spatially resolved PGSE NV-NMR experiments to probe anisotropic water diffusion within a model microstructure. Our method will extend the current capabilities of investigating diffusion processes to the microscopic length scale with the potential of probing single-cells, tissue microstructures, or ion mobility in thin film materials for battery applications.},

keywords = {Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Thermal site energy fluctuations in photosystem I: new insights from MD/QM/MM calculations},

author = {S Reiter and F L Kiss and J Hauer and R De Vivie-Riedle},

url = {http://dx.doi.org/10.1039/D2SC06160K},

doi = {10.1039/D2SC06160K},

issn = {2041-6520},

year  = {2023},

date = {2023-02-06},

journal = {Chemical Science},

volume = {14},

number = {12},

pages = {3117-3131},

abstract = {Cyanobacterial photosystem I (PSI) is one of the most efficient photosynthetic machineries found in nature. Due to the large scale and complexity of the system, the energy transfer mechanism from the antenna complex to the reaction center is still not fully understood. A central element is the accurate evaluation of the individual chlorophyll excitation energies (site energies). Such an evaluation must include a detailed treatment of site specific environmental influences on structural and electrostatic properties, but also their evolution in the temporal domain, because of the dynamic nature of the energy transfer process. In this work, we calculate the site energies of all 96 chlorophylls in a membrane-embedded model of PSI. The employed hybrid QM/MM approach using the multireference DFT/MRCI method in the QM region allows to obtain accurate site energies under explicit consideration of the natural environment. We identify energy traps and barriers in the antenna complex and discuss their implications for energy transfer to the reaction center. Going beyond previous studies, our model also accounts for the molecular dynamics of the full trimeric PSI complex. Via statistical analysis we show that the thermal fluctuations of single chlorophylls prevent the formation of a single prominent energy funnel within the antenna complex. These findings are also supported by a dipole exciton model. We conclude that energy transfer pathways may form only transiently at physiological temperatures, as thermal fluctuations overcome energy barriers. The set of site energies provided in this work sets the stage for theoretical and experimental studies on the highly efficient energy transfer mechanisms in PSI.},

keywords = {Molecularly-Functionalized, Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Mechanisms of Degradation of Na2Ni[Fe(CN)6] Functional Electrodes in Aqueous Media: A Combined Theoretical and Experimental Study},

author = {X Lamprecht and I Evazzade and I Ungerer and L Hromadko and J M Macak and A S Bandarenka and V Alexandrov},

url = {https://doi.org/10.1021/acs.jpcc.2c08222},

doi = {10.1021/acs.jpcc.2c08222},

issn = {1932-7447},

year  = {2023},

date = {2023-01-30},

journal = {The Journal of Physical Chemistry C},

volume = {127},

number = {5},

pages = {2204-2214},

abstract = {Prussian blue analogues (PBAs) are versatile functional materials with numerous applications ranging from electrocatalysis and batteries to sensors and electrochromic devices. Their electrochemical performance involving long-term cycling stability strongly depends on the electrolyte composition. In this work, we use density functional theory calculations and experiments to elucidate the mechanisms of degradation of model Na2Ni[Fe(CN)6] functional electrodes in aqueous electrolytes. Next to the solution pH and cation concentration, we identify anion adsorption as a major driving force for electrode dissolution. Notably, the nature of adsorbed anions can control the mass and charge transfer mechanisms during metal cation intercalation as well as the electrode degradation rate. We find that weakly adsorbing anions, such as NO3\textendash, impede the degradation, while strongly adsorbing anions, such as SO42\textendash, accelerate it. The results of this study provide practical guidelines for electrolyte optimization and can likely be extrapolated to the whole family of PBAs operating in aqueous media.},

keywords = {Foundry Inorganic, Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Does cluster encapsulation inhibit sintering? Stabilization of size-selected Pt clusters on Fe $ _3 $ O $ _4 $(001) by SMSI},

author = {S Kaiser and J Plansky and M Krinninger and A Shavorskiy and S Zhu and U Heiz and F Esch and B A J Lechner},

url = {https://arxiv.org/abs/2301.10845},

doi = {https://doi.org/10.48550/arXiv.2301.10845},

year  = {2023},

date = {2023-01-25},

urldate = {2023-01-25},

journal = {arXiv preprint arXiv:2301.10845},

abstract = {The metastability of supported metal nanoparticles limits their application in heterogeneous catalysis at elevated temperatures due to their tendency to sinter. One strategy to overcome these thermodynamic limits on reducible oxide supports is encapsulation via strong metal-support interaction (SMSI). While annealing-induced encapsulation is a well-explored phenomenon for extended nanoparticles, it is as yet unknown whether the same mechanisms hold for sub-nanometer clusters, where concomitant sintering and alloying might play a significant role. In this article, we explore the encapsulation and stability of size-selected Pt5, Pt10 and Pt19 clusters deposited on Fe3O4(001). In a multimodal approach using temperature-programmed desorption (TPD), x-ray photoelectron spectroscopy (XPS) and scanning tunneling microscopy (STM), we demonstrate that SMSI indeed leads to the formation of a defective, FeO-like conglomerate encapsulating the clusters. By stepwise annealing up to 1023 K, we observe the succession of encapsulation, cluster coalescence and Ostwald ripening, resulting in square-shaped crystalline Pt particles, independent of the initial cluster sizes. The respective sintering onset temperatures scale with the cluster footprint and thus size. Remarkably, while small encapsulated clusters can still diffuse as a whole, atom detachment and thus Ostwald ripening are successfully suppressed up to 823 K, i.e. 200 K above the H\"{u}ttig temperature that indicates the thermodynamic stability limit.},

keywords = {Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Covalent Organic Framework Thin-Film Photodetectors from Solution-Processable Porous Nanospheres},

author = {S Bag and H S Sasmal and S P Chaudhary and K Dey and D Bl\"{a}tte and R Guntermann and Y Zhang and M Polo\v{z}ij and A Kuc and A Shelke and R K Vijayaraghavan and T G Ajithkumar and S Bhattacharyya and T Heine and T Bein and R Banerjee},

url = {https://doi.org/10.1021/jacs.2c09838},

doi = {10.1021/jacs.2c09838},

issn = {0002-7863},

year  = {2023},

date = {2023-01-09},

journal = {Journal of the American Chemical Society},

volume = {145},

number = {3},

pages = {1649-1659},

abstract = {The synthesis of homogeneous covalent organic framework (COF) thin films on a desired substrate with decent crystallinity, porosity, and uniform thickness has great potential for optoelectronic applications. We have used a solution-processable sphere transmutation process to synthesize 300 ± 20 nm uniform COF thin films on a 2 × 2 cm2 TiO2-coated fluorine-doped tin oxide (FTO) surface. This process controls the nucleation of COF crystallites and molecular morphology that helps the nanospheres to arrange periodically to form homogeneous COF thin films. We have synthesized four COF thin films (TpDPP, TpEtBt, TpTab, and TpTta) with different functional backbones. In a close agreement between the experiment and density functional theory, the TpEtBr COF film showed the lowest optical band gap (2.26 eV) and highest excited-state lifetime (8.52 ns) among all four COF films. Hence, the TpEtBr COF film can participate in efficient charge generation and separation. We constructed optoelectronic devices having a glass/FTO/TiO2/COF-film/Au architecture, which serves as a model system to study the optoelectronic charge transport properties of COF thin films under dark and illuminated conditions. Visible light with a calibrated intensity of 100 mW cm\textendash2 was used for the excitation of COF thin films. All of the COF thin films exhibit significant photocurrent after illumination with visible light in comparison to the dark. Hence, all of the COF films behave as good photoactive substrates with minimal pinhole defects. The fabricated out-of-plane photodetector device based on the TpEtBr COF thin film exhibits high photocurrent density (2.65 ± 0.24 mA cm\textendash2 at 0.5 V) and hole mobility (8.15 ± 0.64 ×10\textendash3 cm2 V\textendash1 S\textendash1) compared to other as-synthesized films, indicating the best photoactive characteristics.},

keywords = {Foundry Organic, Molecularly-Functionalized, Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Spatially-Modulated Silicon Interface Energetics Via Hydrogen Plasma-Assisted Atomic Layer Deposition of Ultrathin Alumina},

author = {A Henning and J D Bartl and L Wolz and M Christis and F Rauh and M Bissolo and T Gr\"{u}nleitner and J Eichhorn and P Zeller and M Amati and L Gregoratti and J J Finley and B Rieger and M Stutzmann and I D Sharp},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/admi.202202166},

doi = {https://doi.org/10.1002/admi.202202166},

issn = {2196-7350},

year  = {2022},

date = {2022-12-16},

journal = {Advanced Materials Interfaces},

volume = {n/a},

number = {n/a},

pages = {2202166},

abstract = {Abstract Atomic layer deposition (ALD) is a key technique for the continued scaling of semiconductor devices, which increasingly relies on scalable processes for interface manipulation of structured surfaces on the atomic level. While ALD allows the synthesis of conformal films with utmost control over the thickness, atomically-defined closed coatings and surface modifications are challenging to achieve because of 3D growth during nucleation. Here, a route is presented toward the sub-nanometer thin and continuous aluminum oxide (AlOx) coatings on silicon substrates for the spatial control of the surface charge density and interface energetics. Trimethylaluminum in combination with remote hydrogen plasma is used instead of a gas-phase oxidant for the transformation of silicon dioxide (SiO2) into alumina. Depending on the number of ALD cycles, the SiO2 can be partially or fully transformed, which is exploited to deposit ultrathin AlOx layers in selected regions defined by lithographic patterning. The resulting patterned surfaces are characterized by lateral AlOx/SiO2 interfaces possessing 0.3 nm step heights and surface potential steps exceeding 0.4 V. In addition, the introduction of fixed negative charges of 9 × 1012 cm−2 enables modulation of the surface band bending, which is relevant to the field-effect passivation of silicon and low-impedance charge transfer across contact interfaces.},

keywords = {Molecularly-Functionalized, Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Gold\textendashRhodium Nanoflowers for the Plasmon-Enhanced CO2 Electroreduction Reaction upon Visible Light},

author = {M P S Rodrigues and A H B Dourado and A G Sampaio De Oliveira-Filho and A P De Lima Batista and M Feil and K Krischer and S I C\'{o}rdoba De Torresi},

url = {https://doi.org/10.1021/acscatal.2c04207},

doi = {10.1021/acscatal.2c04207},

year  = {2022},

date = {2022-12-15},

journal = {ACS Catalysis},

pages = {267-279},

abstract = {Bimetallic nanostructures combining catalytic and plasmonic properties are a class of materials that might possess improved efficiency and/or selectivity in electrocatalytic reactions. In this paper, we described the application of gold\textendashrhodium core\textendashshell nanoflowers (Au@Rh NFs) as a model system for the electrochemical CO2 reduction reaction. The nanoparticles consist of a gold nucleus surrounded by rhodium branches, combining Au localized surface plasmon resonance (LSPR) in the visible range of the spectrum and Rh catalytic properties. The influence of LSPR excitation on the catalytic properties was evaluated for different excitation wavelengths and various Au@Rh NF metallic ratios. Our catalysts showed enhanced activity upon LSPR excitation, demonstrating that LSPR excitation may lead to improved performance even with a low content of metallic NFs (2% Au + Rh in Carbon Vulcan). Electrochemical impedance spectroscopy (EIS) experiments performed under LSPR excitation suggest that the superior activity under illumination is related to lower energetic barriers that facilitate the desorption of adsorbed species compared to dark conditions.L},

keywords = {Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Combining impedance and hydrodynamic methods in electrocatalysis. Characterization of Pt(pc), Pt5Gd, and nanostructured Pd for the hydrogen evolution reaction},

author = {K-T Song and C M Schott and P M Schneider and S A Watzele and R M Kluge and E L Gubanova and A S Bandarenka},

url = {http://iopscience.iop.org/article/10.1088/2515-7655/acabe5},

issn = {2515-7655},

year  = {2022},

date = {2022-12-15},

journal = {Journal of Physics: Energy},

abstract = {Electrochemical hydrodynamic techniques typically involve electrodes that move relative to the solution. Historically, approaches involving rotating disc electrode (RDE) configurations have become very popular, as one can easily control the electroactive species' mass transport in those cases. The combination of cyclic voltammetry and RDE is nowadays one of the standard characterization protocols in electrocatalysis. On the other hand, impedance spectroscopy is one of the most informative electrochemistry techniques, enabling the acquisition of information on the processes taking place simultaneously at the electrode/electrolyte interface. In this work, we investigated the hydrogen evolution reaction (HER) catalyzed by polycrystalline Pt (Pt(pc)) and Pt5Gd disc electrodes and characterized them using RDE and EIS techniques simultaneously. Pt5Gd shows higher HER activities than Pt in acidic and alkaline media due to strain and ligand effects. The mechanistic study of the reaction showed that the rotation rates in acidic media have no effect on the contribution of the Volmer-Heyrovsky and Volmer-Tafel pathways. However, the Volmer-Heyrovsky pathway dominates at lower rotation rates in alkaline media. Besides, the HER in acidic solutions depends more strongly on mass diffusion than in alkaline media. In addition to simple and clearly defined systems, the combined method of both techniques is applicable for systems with greater complexity, such as Pd/C nanostructured catalysts. Applying the above-presented approach, we found that the Volmer-Tafel pathway is the dominating mechanism of the HER for this catalytic system.},

keywords = {Foundry Inorganic, Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Real-Time Investigation of Sulfur Vacancy Generation and Passivation in Monolayer Molybdenum Disulfide via in situ X-ray Photoelectron Spectromicroscopy},

author = {T Gr\"{u}nleitner and A Henning and M Bissolo and M Zengerle and L Gregoratti and M Amati and P Zeller and J Eichhorn and A V Stier and A W Holleitner and J J Finley and I D Sharp},

url = {https://doi.org/10.1021/acsnano.2c06317},

doi = {10.1021/acsnano.2c06317},

issn = {1936-0851},

year  = {2022},

date = {2022-12-14},

journal = {ACS Nano},

abstract = {Understanding the chemical and electronic properties of point defects in two-dimensional materials, as well as their generation and passivation, is essential for the development of functional systems, spanning from next-generation optoelectronic devices to advanced catalysis. Here, we use synchrotron-based X-ray photoelectron spectroscopy (XPS) with submicron spatial resolution to create sulfur vacancies (SVs) in monolayer MoS2 and monitor their chemical and electronic properties in situ during the defect creation process. X-ray irradiation leads to the emergence of a distinct Mo 3d spectral feature associated with undercoordinated Mo atoms. Real-time analysis of the evolution of this feature, along with the decrease of S content, reveals predominant monosulfur vacancy generation at low doses and preferential disulfur vacancy generation at high doses. Formation of these defects leads to a shift of the Fermi level toward the valence band (VB) edge, introduction of electronic states within the VB, and formation of lateral pn junctions. These findings are consistent with theoretical predictions that SVs serve as deep acceptors and are not responsible for the ubiquitous n-type conductivity of MoS2. In addition, we find that these defects are metastable upon short-term exposure to ambient air. By contrast, in situ oxygen exposure during XPS measurements enables passivation of SVs, resulting in partial elimination of undercoordinated Mo sites and reduction of SV-related states near the VB edge. Correlative Raman spectroscopy and photoluminescence measurements confirm our findings of localized SV generation and passivation, thereby demonstrating the connection between chemical, structural, and optoelectronic properties of SVs in MoS2.},

keywords = {Foundry Inorganic, Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Using Metal\textendashOrganic Frameworks to Confine Liquid Samples for Nanoscale NV-NMR},

author = {K S Liu and X Ma and R Rizzato and A L Semrau and A Henning and I D Sharp and R A Fischer and D B Bucher},

url = {https://doi.org/10.1021/acs.nanolett.2c03069},

doi = {10.1021/acs.nanolett.2c03069},

issn = {1530-6984},

year  = {2022},

date = {2022-12-08},

journal = {Nano Letters},

abstract = {Atomic-scale magnetic field sensors based on nitrogen vacancy (NV) defects in diamonds are an exciting platform for nanoscale nuclear magnetic resonance (NMR) spectroscopy. The detection of NMR signals from a few zeptoliters to single molecules or even single nuclear spins has been demonstrated using NV centers close to the diamond surface. However, fast molecular diffusion of sample molecules in and out of the nanoscale detection volumes impedes their detection and limits current experiments to solid-state or highly viscous samples. Here, we show that restricting diffusion by confinement enables nanoscale NMR spectroscopy of liquid samples. Our approach uses metal\textendashorganic frameworks (MOF) with angstrom-sized pores on a diamond chip to trap sample molecules near the NV centers. This enables the detection of NMR signals from a liquid sample, which would not be detectable without confinement. These results set the route for nanoscale liquid-phase NMR with high spectral resolution.},

keywords = {Molecularly-Functionalized, Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Microfluidic quantum sensing platform for lab-on-a-chip applications},

author = {R D Allert and F Bruckmaier and N R Neuling and F A Freire-Moschovitis and K S Liu and C Schrepel and P Sch\"{a}tzle and P Knittel and M Hermans and D B Bucher},

url = {http://dx.doi.org/10.1039/D2LC00874B},

doi = {10.1039/D2LC00874B},

issn = {1473-0197},

year  = {2022},

date = {2022-11-10},

journal = {Lab on a Chip},

volume = {22},

number = {24},

pages = {4831-4840},

abstract = {Lab-on-a-chip (LOC) applications have emerged as invaluable physical and life sciences tools. The advantages stem from advanced system miniaturization, thus, requiring far less sample volume while allowing for complex functionality, increased reproducibility, and high throughput. However, LOC applications necessitate extensive sensor miniaturization to leverage these inherent advantages fully. Atom-sized quantum sensors are highly promising to bridge this gap and have enabled measurements of temperature, electric and magnetic fields on the nano- to microscale. Nevertheless, the technical complexity of both disciplines has so far impeded an uncompromising combination of LOC systems and quantum sensors. Here, we present a fully integrated microfluidic platform for solid-state spin quantum sensors, like the nitrogen-vacancy (NV) center in diamond. Our platform fulfills all technical requirements, such as fast spin manipulation, enabling full quantum sensing capabilities, biocompatibility, and easy adaptability to arbitrary channel and chip geometries. To illustrate the vast potential of quantum sensors in LOC systems, we demonstrate various NV center-based sensing modalities for chemical analysis in our microfluidic platform, ranging from paramagnetic ion detection to high-resolution microscale NV-NMR. Consequently, our work opens the door for novel chemical analysis capabilities within LOC devices with applications in electrochemistry, high-throughput reaction screening, bioanalytics, organ-on-a-chip, or single-cell studies.},

keywords = {Molecularly-Functionalized, Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Alkali metal cations change the hydrogen evolution reaction mechanisms at Pt electrodes in alkaline media},

author = {Y Taji and A Zagalskaya and I Evazzade and S Watzele and K-T Song and S Xue and C Schott and B Garlyyev and V Alexandrov and E Gubanova and A S Bandarenka},

url = {https://www.sciencedirect.com/science/article/pii/S2589965122000514},

doi = {https://doi.org/10.1016/j.nanoms.2022.09.003},

issn = {2589-9651},

year  = {2022},

date = {2022-10-29},

journal = {Nano Materials Science},

abstract = {The effects of seemingly inert alkali metal (AM) cations on the electrocatalytic activity of electrode materials towards reactions essential for energy provision have become the emphasis of substantial research efforts in recent years. The hydrogen and oxygen evolution reactions during alkaline water electrolysis and the oxygen electro-reduction taking place in fuel cells are of particular importance. There is no universal theory explaining all the details of the AM cation effect in electrocatalysis. For example, it remains unclear how “spectator” AM-cations can change the kinetics of electrocatalytic reactions often more significantly than the modifications of the electrode structure and composition. This situation originates partly from a lack of systematic experimental and theoretical studies of this phenomenon. The present work exploits impedance spectroscopy to investigate the influence of the AM cations on the mechanism of the hydrogen evolution reaction at Pt microelectrodes. The activity follows the trend: Li+≥Na+\>K+\>Cs+, where the highest activity corresponds to 0.1 ​M LiOH electrolytes at low overpotentials. We demonstrate that the nature of the AM cations also changes the relative contribution of the Volmer\textendashHeyrovsky and Volmer\textendashTafel mechanisms to the overall reaction, with the former being more important for LiOH electrolytes. Our density functional theory-based thermodynamics and molecular dynamics calculations support these findings.},

keywords = {Foundry Inorganic, Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Q-Band relaxation in chlorophyll: new insights from multireference quantum dynamics},

author = {S Reiter and L B\"{a}uml and J Hauer and R De Vivie-Riedle},

url = {http://dx.doi.org/10.1039/D2CP02914F},

doi = {10.1039/D2CP02914F},

issn = {1463-9076},

year  = {2022},

date = {2022-10-27},

journal = {Physical Chemistry Chemical Physics},

abstract = {The ultrafast relaxation within the Q-bands of chlorophyll plays a crucial role in photosynthetic light-harvesting. Yet, despite being the focus of many experimental and theoretical studies, it is still not fully understood. In this paper we look at the relaxation process from the perspective of non-adiabatic wave packet dynamics. For this purpose, we identify vibrational degrees of freedom which contribute most to the non-adiabatic coupling. Using a selection of normal modes, we construct four reduced-dimensional coordinate spaces and investigate the wave packet dynamics on XMS-CASPT2 potential energy surfaces. In this context, we discuss the associated computational challenges, as many quantum chemical methods overestimate the Qx\textendashQy energy gap. Our results show that the Qx and Qy potential energy surfaces do not cross in an energetically accessible region of the vibrational space. Instead, non-adiabatic coupling facilitates ultrafast population transfer across the potential energy surface. Moreover, we can identify the excited vibrational eigenstates that take part in the relaxation process. We conclude that the Q-band system of chlorophyll a should be viewed as a strongly coupled system, where population is easily transferred between the x and y-polarized electronic states. This suggests that both orientations may contribute to the electron transfer in the reaction center of photosynthetic light-harvesting systems.},

keywords = {Molecularly-Functionalized, Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Emerging noble metal-free Mo-based bifunctional catalysts for electrochemical energy conversion},

author = {S Santra and V Streibel and I D Sharp},

url = {https://doi.org/10.1007/s12274-022-5022-y},

doi = {10.1007/s12274-022-5022-y},

issn = {1998-0000},

year  = {2022},

date = {2022-10-22},

journal = {Nano Research},

volume = {15},

number = {12},

pages = {10234-10267},

abstract = {The transition from a global economy dependent on fossil fuels to one based on sustainable energy conversion technologies presents the primary challenge of the day. Equipping water electrolyzers and metal-air batteries with earth-abundant bifunctional transition metal (TM) catalysts that efficiently catalyse the hydrogen and oxygen evolution reactions (HER and OER) and the oxygen reduction and evolution reactions (ORR and OER), respectively, reduces the cost and system complexity, while also providing prospects for accelerated scaling and sustainable material reuse. Among the TMs, earth-abundant molybdenum (Mo)-based multifunctional catalysts are especially promising and have attracted considerable attention in recent years. Starting with a brief introduction to HER, OER, and ORR mechanisms and parameters governing their bifunctionality, this comprehensive review focuses on such Mo-based multifunctional catalysts. We review and discuss recent progress achieved through the formation of Mo-based compounds, heterostructures, and nanoscale composites, as well as by doping, defect engineering, and nanoscale sculpting of Mo-based catalysts. The systems discussed in detail are based on Mo chalcogenides, carbides, oxides, nitrides, and phosphides, as well as Mo alloys, highlighting specific opportunities afforded by synergistic interactions of Mo with both non-metals and non-noble metals. Finally, we discuss the future of Mo-based multifunctional electrocatalysts for HER/OER, ORR/OER, and HER/ORR/OER, analysing emerging trends, new opportunities, and underexplored avenues in this promising materials space.},

keywords = {Molecularly-Functionalized, Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Phase-Selective Four-Wave Mixing of Resonant Plasmonic Nanoantennas},

author = {V Giegold and K Ko\la̧Taj and T Liedl and A Hartschuh},

url = {https://doi.org/10.1021/acsphotonics.2c01362},

doi = {10.1021/acsphotonics.2c01362},

year  = {2022},

date = {2022-10-11},

journal = {ACS Photonics},

abstract = {Metallic nanoantennas are key components of a wide range of optical techniques that exploit their plasmonic response for signal amplification and extremely sensitive detection. For nonlinear techniques, the higher-order plasmonic response of a nanoantenna can be predicted by the product of the nanoantenna’s linear susceptibilities, known as Miller’s rule, provided that the spatial field distributions at the fundamental and the nonlinear frequencies are the same. Here, we show that Miller’s rule also holds for ultra-broadband excitation pulses and that it can be utilized to predict the frequency dependence of the near-degenerate four-wave mixing (ND-FWM) intensities generated by individual resonant plasmonic nanoantennas. Importantly, this implies that the nanoantenna’s nonlinear response can be deterministically controlled and further optimized by varying the spectral phase of the laser pulse. We demonstrate this by measuring the chirp dependence of the ND-FWM signal and observe an enhancement of up to 60% depending on the position of the plasmon resonance with respect to the laser spectrum, in agreement with model predictions. Finally, we exploit this phase control for chirp-selective confocal imaging of resonant nanoantennas. Our findings may help improve the sensitivity of nonlinear techniques such as plasmon-enhanced coherent anti-Stokes Raman scattering.},

keywords = {Molecularly-Functionalized, Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Tuning Strong Metal\textendashSupport Interaction Kinetics on Pt-Loaded TiO2(110) by Choosing the Pressure: A Combined Ultrahigh Vacuum/Near-Ambient Pressure XPS Study},

author = {P Petzoldt and M Eder and S Mackewicz and M Blum and T Kratky and S G\"{u}nther and M Tschurl and U Heiz and B A J Lechner},

url = {https://doi.org/10.1021/acs.jpcc.2c03851},

doi = {10.1021/acs.jpcc.2c03851},

issn = {1932-7447},

year  = {2022},

date = {2022-09-29},

urldate = {2022-09-29},

journal = {The Journal of Physical Chemistry C},

volume = {126},

number = {38},

pages = {16127-16139},

abstract = {Pt catalyst particles on reducible oxide supports often change their activity significantly at elevated temperatures due to the strong metal\textendashsupport interaction (SMSI), which induces the formation of an encapsulation layer around the noble metal particles. However, the impact of oxidizing and reducing treatments at elevated pressures on this encapsulation layer remains controversial, partly due to the “pressure gap” between surface science studies and applied catalysis. In the present work, we employ synchrotron-based near-ambient pressure X-ray photoelectron spectroscopy (NAP-XPS) to study the effect of O2 and H2 on the SMSI-state of well-defined Pt/TiO2(110) catalysts at pressures of up to 0.1 Torr. By tuning the O2 pressure, we can either selectively oxidize the TiO2 support or both the support and the Pt particles. Catalyzed by metallic Pt, the encapsulating oxide overlayer grows rapidly in 1 × 10\textendash5 Torr O2, but orders of magnitude less effectively at higher O2 pressures, where Pt is in an oxidic state. While the oxidation/reduction of Pt particles is reversible, they remain embedded in the support once encapsulation has occurred.},

keywords = {Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Tuning Strong Metal\textendashSupport Interaction Kinetics on Pt-Loaded TiO2(110) by Choosing the Pressure: A Combined Ultrahigh Vacuum/Near-Ambient Pressure XPS Study},

author = {P Petzoldt and M Eder and S Mackewicz and M Blum and T Kratky and S G\"{u}nther and M Tschurl and U Heiz and B A J Lechner},

url = {https://doi.org/10.1021/acs.jpcc.2c03851},

doi = {10.1021/acs.jpcc.2c03851},

issn = {1932-7447},

year  = {2022},

date = {2022-09-16},

urldate = {2022-09-16},

journal = {The Journal of Physical Chemistry C},

volume = {126},

number = {38},

pages = {16127-16139},

abstract = {Pt catalyst particles on reducible oxide supports often change their activity significantly at elevated temperatures due to the strong metal\textendashsupport interaction (SMSI), which induces the formation of an encapsulation layer around the noble metal particles. However, the impact of oxidizing and reducing treatments at elevated pressures on this encapsulation layer remains controversial, partly due to the “pressure gap” between surface science studies and applied catalysis. In the present work, we employ synchrotron-based near-ambient pressure X-ray photoelectron spectroscopy (NAP-XPS) to study the effect of O2 and H2 on the SMSI-state of well-defined Pt/TiO2(110) catalysts at pressures of up to 0.1 Torr. By tuning the O2 pressure, we can either selectively oxidize the TiO2 support or both the support and the Pt particles. Catalyzed by metallic Pt, the encapsulating oxide overlayer grows rapidly in 1 × 10\textendash5 Torr O2, but orders of magnitude less effectively at higher O2 pressures, where Pt is in an oxidic state. While the oxidation/reduction of Pt particles is reversible, they remain embedded in the support once encapsulation has occurred.},

keywords = {Foundry Inorganic, Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Introducing a Symmetry-Breaking Coupler into a Dielectric Metasurface Enables Robust High-Q Quasi-BICs},

author = {G Q Moretti and A Tittl and E Cort\'{e}s and S A Maier and A V Bragas and G Grinblat},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/adpr.202200111},

doi = {https://doi.org/10.1002/adpr.202200111},

issn = {2699-9293},

year  = {2022},

date = {2022-08-21},

journal = {Advanced Photonics Research},

volume = {n/a},

number = {n/a},

pages = {2200111},

abstract = {Dielectric metasurfaces supporting quasibound states in the continuum (quasi-BICs) exhibit very high-quality factor resonances and electric field confinement. However, accessing the high-Q end of the quasi-BIC regime usually requires marginally distorting the metasurface design from a BIC condition, pushing the needed nanoscale fabrication precision to the limit. This work introduces a novel concept for generating high-Q quasi-BICs, which strongly relaxes this requirement by incorporating a relatively large perturbative element close to high-symmetry points of an undistorted BIC metasurface, acting as a coupler to the radiation continuum. This approach is validated by adding a ≈100 nm diameter cylinder between two reflection-symmetry points separated by a 300 nm gap in an elliptical disk metasurface unit cell, using gallium phosphide as the dielectric. It is found that high-Q resonances emerge when the cylindrical coupler is placed at any position between such symmetry points. This metasurface's second harmonic generation capability in the optical range is further explored. Displacing the coupler as much as a full diameter from a BIC condition produces record-breaking normalized conversion efficiencies \>102 W−1. The strategy of enclosing a disruptive element between multiple high-symmetry points in a BIC metasurface can be applied to construct robust high-Q quasi-BICs in many geometrical designs.},

keywords = {Foundry Inorganic, Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Strong Polarization Dependent Nonlinear Excitation of a Perovskite Nanocrystal Monolayer on a Chiral Dielectric Nanoantenna Array},

author = {I Vin\c{c}on and F J Wendisch and D De Gregorio and S D Pritzl and Q A Akkerman and H Ren and L De S. Menezes and S A Maier and J Feldmann},

url = {https://doi.org/10.1021/acsphotonics.2c00159},

doi = {10.1021/acsphotonics.2c00159},

year  = {2022},

date = {2022-08-17},

journal = {ACS Photonics},

abstract = {With their unique optoelectronic properties, perovskite nanocrystals are highly advantageous semiconductor materials for tailored light applications including an interaction with circularly polarized light. Although chiral perovskite nanocrystals have been obtained by the adsorption of chiral molecules, their chiroptical response is still intrinsically weak. Alternatively, perovskites have been combined with artificial chiral surfaces demonstrating enhanced chiroptical responses. However, bulk perovskite films of considerable thickness were required, mitigating the perovskite’s photoluminescence efficiency and processability. Here we developed a hybrid system of a dielectric chiral nanoantenna array that was coated with a monolayer of cubic all-inorganic lead halide perovskite nanocrystals. By tuning the thickness of the perovskite film down to one monolayer of nanocrystals, we restricted the interactions exclusively to the near-field regime. The chiral surface built of z-shaped Si nanoantennas features pronounced chiral resonances in the visible to IR region. We demonstrate that the two-photon excited photoluminescence emission of the nanocrystals can be enhanced by up to one order of magnitude in this configuration. This emission increase is controllable by the choice of the excitation wavelength and polarization with an asymmetry in emission of up to 25% upon left and right circularly polarized illumination. Altogether, our findings demonstrate a pathway to an all-optical control and modulation of perovskite light emission via strong polarization sensitive light\textendashmatter interactions in the near-field, rendering this hybrid system interesting for sensing and display technologies.},

keywords = {Molecularly-Functionalized, Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Identification of the Highly Active Co\textendashN4 Coordination Motif for Selective Oxygen Reduction to Hydrogen Peroxide},

author = {S Chen and T Luo and X Li and K Chen and J Fu and K Liu and C Cai and Q Wang and H Li and Y Chen and C Ma and L Zhu and Y-R Lu and T-S Chan and M Zhu and E Cort\'{e}s and M Liu},

url = {https://doi.org/10.1021/jacs.2c01194},

doi = {10.1021/jacs.2c01194},

issn = {0002-7863},

year  = {2022},

date = {2022-08-03},

journal = {Journal of the American Chemical Society},

volume = {144},

number = {32},

pages = {14505-14516},

abstract = {Electrosynthesis of hydrogen peroxide (H2O2) through oxygen reduction reaction (ORR) is an environment-friendly and sustainable route for obtaining a fundamental product in the chemical industry. Co\textendashN4 single-atom catalysts (SAC) have sparkled attention for being highly active in both 2e\textendash ORR, leading to H2O2 and 4e\textendash ORR, in which H2O is the main product. However, there is still a lack of fundamental insights into the structure\textendashfunction relationship between CoN4 and the ORR mechanism over this family of catalysts. Here, by combining theoretical simulation and experiments, we unveil that pyrrole-type CoN4 (Co\textendashN SACDp) is mainly responsible for the 2e\textendash ORR, while pyridine-type CoN4 catalyzes the 4e\textendash ORR. Indeed, Co\textendashN SACDp exhibits a remarkable H2O2 selectivity of 94% and a superb H2O2 yield of 2032 mg for 90 h in a flow cell, outperforming most reported catalysts in acid media. Theoretical analysis and experimental investigations confirm that Co\textendashN SACDp─with weakening O2/HOO* interaction─boosts the H2O2 production.},

keywords = {Molecularly-Functionalized, Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Ordered Ag Nanoneedle Arrays with Enhanced Electrocatalytic CO2 Reduction via Structure-Induced Inhibition of Hydrogen Evolution},

author = {Q Chen and K Liu and Y Zhou and X Wang and K Wu and H Li and E Pensa and J Fu and M Miyauchi and E Cort\'{e}s and M Liu},

url = {https://doi.org/10.1021/acs.nanolett.2c01853},

doi = {10.1021/acs.nanolett.2c01853},

issn = {1530-6984},

year  = {2022},

date = {2022-08-01},

journal = {Nano Letters},

volume = {22},

number = {15},

pages = {6276-6284},

abstract = {Silver is an attractive catalyst for converting CO2 into CO. However, the high CO2 activation barrier and the hydrogen evolution side reaction seriously limit its practical application and industrial perspective. Here, an ordered Ag nanoneedle array (Ag-NNAs) was prepared by template-assisted vacuum thermal-evaporation for CO2 electroreduction into CO. The nanoneedle array structure induces a strong local electric field at the tips, which not only reduces the activation barrier for CO2 electroreduction but also increases the energy barrier for the hydrogen evolution reaction (HER). Moreover, the array structure endows a high surface hydrophobicity, which can regulate the adsorption of water molecules at the interface and thus dynamically inhibit the competitive HER. As a result, the optimal Ag-NNAs exhibits 91.4% Faradaic efficiency (FE) of CO for over 700 min at −1.0 V vs RHE. This work provides a new concept for the application of nanoneedle array structures in electrocatalytic CO2 reduction reactions.},

keywords = {Molecularly-Functionalized, Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Mechanistic Insights into OC\textendashCOH Coupling in CO2 Electroreduction on Fragmented Copper},

author = {K Yao and J Li and H Wang and R Lu and X Yang and M Luo and N Wang and Z Wang and C Liu and T Jing and S Chen and E Cort\'{e}s and S A Maier and S Zhang and T Li and Y Yu and Y Liu and X Kang and H Liang},

url = {https://doi.org/10.1021/jacs.2c01044},

doi = {10.1021/jacs.2c01044},

issn = {0002-7863},

year  = {2022},

date = {2022-07-29},

journal = {Journal of the American Chemical Society},

volume = {144},

number = {31},

pages = {14005-14011},

abstract = {The carbon\textendashcarbon (C\textendashC) bond formation is essential for the electroconversion of CO2 into high-energy-density C2+ products, and the precise coupling pathways remain controversial. Although recent computational investigations have proposed that the OC\textendashCOH coupling pathway is more favorable in specific reaction conditions than the well-known CO dimerization pathway, the experimental evidence is still lacking, partly due to the separated catalyst design and mechanistic/spectroscopic exploration. Here, we employ density functional theory calculations to show that on low-coordinated copper sites, the *CO bindings are strengthened, and the adsorbed *CO coupling with their hydrogenation species, *COH, receives precedence over CO dimerization. Experimentally, we construct a fragmented Cu catalyst with abundant low-coordinated sites, exhibiting a 77.8% Faradaic efficiency for C2+ products at 300 mA cm\textendash2. With a suite of in situ spectroscopic studies, we capture an *OCCOH intermediate on the fragmented Cu surfaces, providing direct evidence to support the OC\textendashCOH coupling pathway. The mechanistic insights of this research elucidate how to design materials in favor of OC\textendashCOH coupling toward efficient C2+ production from CO2 reduction.},

keywords = {Molecularly-Functionalized, Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Size and Coverage Effects of Ni and Pt Co-Catalysts in the Photocatalytic Hydrogen Evolution from Methanol on TiO2(110)},

author = {M Eder and C Courtois and P Petzoldt and S Mackewicz and M Tschurl and U Heiz},

url = {https://doi.org/10.1021/acscatal.2c02230},

doi = {10.1021/acscatal.2c02230},

year  = {2022},

date = {2022-07-21},

journal = {ACS Catalysis},

pages = {9579-9588},

abstract = {In the past decade, hydrogen evolution from photocatalytic alcohol oxidation on metal-loaded TiO2 has emerged as an active research field. While the presence of a metal cluster co-catalyst is crucial as a H2 recombination center, size and coverage effects on the catalyst performance are not yet comprehensively understood. To some extent, this is due to the fact that common deposition methods do not allow for an independent change in size and coverage, which can be overcome by the use of cluster sources and the deposition of size-selected clusters. This study compares size-selected Ni and Pt clusters as co-catalysts on a TiO2(110) single crystal and the resulting size- and coverage-dependent effects in the photocatalytic hydrogen evolution from alcohols in ultrahigh vacuum (UHV). Larger clusters and higher coverages of Ni enhance the product formation rate, although deactivation over time occurs. In contrast, Pt co-catalysts exhibit a stable and higher activity and size-specific effects have to be taken into account. While H2 evolution is improved by a higher concentration of Pt clusters, an increase in the metal content by the deposition of larger particles can even be detrimental to the performance of the photocatalyst. The acquired overall mechanistic picture is corroborated by H2 formation kinetics from mass spectrometric data. Consequently, for some metals, size effects are relevant for improving the catalytic performance, while for other co-catalyst materials, merely the coverage is decisive. The elucidation of different size and coverage dependencies represents an important step toward a rational catalyst design for photocatalytic hydrogen evolution.},

keywords = {Foundry Inorganic, Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {In Situ Observation of Morphological and Oxidation Level Degradation Processes within Ionic Liquid Post-treated PEDOT:PSS Thin Films upon Operation at High Temperatures},

author = {A L Oechsle and J E Heger and N Li and S Yin and S Bernstorff and P M\"{u}ller-Buschbaum},

url = {https://doi.org/10.1021/acsami.2c05745},

doi = {10.1021/acsami.2c05745},

issn = {1944-8244},

year  = {2022},

date = {2022-06-27},

journal = {ACS Applied Materials \& Interfaces},

volume = {14},

number = {27},

pages = {30802-30811},

abstract = {Organic thermoelectric thin films are investigated in terms of their stability at elevated operating temperatures. Therefore, the electrical conductivity of ethyl-3-methylimidazolium dicyanamide (EMIM DCA) post-treated poly(3,4-ethylene dioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) thin films is measured over 4.5 h of heating at 50 or 100 °C for different EMIM DCA concentrations. The changes in the electrical performance are correlated with changes in the film morphology, as evidenced with in situ grazing-incidence small-angle X-ray scattering (GISAXS). Due to the overall increased PEDOT domain distances, the resulting impairment of the interdomain charge carrier transport directly correlates with the observed electrical conductivity decay. With in situ ultraviolet−visible (UV\textendashVis) measurements, a simultaneously occurring reduction of the PEDOT oxidation level is found to have an additional electrical conductivity lowering contribution due to the decrease of the charge carrier density. Finally, the observed morphology and oxidation level degradation is associated with the deterioration of the thermoelectric properties and hence a favorable operating temperature range is suggested for EMIM DCA post-treated PEDOT:PSS-based thermoelectrics.},

keywords = {Foundry Inorganic, Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Elucidating the Role of Antisolvents on the Surface Chemistry and Optoelectronic Properties of CsPbBrxI3-x Perovskite Nanocrystals},

author = {J Ye and Z Li and D J Kubicki and Y Zhang and L Dai and C Otero-Mart\'{i}nez and M A Reus and R Arul and K R Dudipala and Z Andaji-Garmaroudi and Y-T Huang and Z Li and Z Chen and P M\"{u}ller-Buschbaum and H-L Yip and S D Stranks and C P Grey and J J Baumberg and N C Greenham and L Polavarapu and A Rao and R L Z Hoye},

url = {https://doi.org/10.1021/jacs.2c02631},

doi = {10.1021/jacs.2c02631},

issn = {0002-7863},

year  = {2022},

date = {2022-06-27},

journal = {Journal of the American Chemical Society},

volume = {144},

number = {27},

pages = {12102-12115},

abstract = {Colloidal lead-halide perovskite nanocrystals (LHP NCs) have emerged over the past decade as leading candidates for efficient next-generation optoelectronic devices, but their properties and performance critically depend on how they are purified. While antisolvents are widely used for purification, a detailed understanding of how the polarity of the antisolvent influences the surface chemistry and composition of the NCs is missing in the field. Here, we fill this knowledge gap by studying the surface chemistry of purified CsPbBrxI3-x NCs as the model system, which in itself is considered a promising candidate for pure-red light-emitting diodes and top-cells for tandem photovoltaics. Interestingly, we find that as the polarity of the antisolvent increases (from methyl acetate to acetone to butanol), there is a blueshift in the photoluminescence (PL) peak of the NCs along with a decrease in PL quantum yield (PLQY). Through transmission electron microscopy and X-ray photoemission spectroscopy measurements, we find that these changes in PL properties arise from antisolvent-induced iodide removal, which leads to a change in halide composition and, thus, the bandgap. Using detailed nuclear magnetic resonance (NMR) and Fourier-transform infrared spectroscopy (FTIR) measurements along with density functional theory calculations, we propose that more polar antisolvents favor the detachment of the oleic acid and oleylamine ligands, which undergo amide condensation reactions, leading to the removal of iodide anions from the NC surface bound to these ligands. This work shows that careful selection of low-polarity antisolvents is a critical part of designing the synthesis of NCs to achieve high PLQYs with minimal defect-mediated phase segregation.},

keywords = {Foundry Inorganic, Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Designing Multifunctional Cobalt Oxide Layers for Efficient and Stable Electrochemical Oxygen Evolution},

author = {M Kuhl and A Henning and L Haller and L I Wagner and C-M Jiang and V Streibel and I D Sharp and J Eichhorn},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/admi.202200582},

doi = {https://doi.org/10.1002/admi.202200582},

issn = {2196-7350},

year  = {2022},

date = {2022-06-24},

journal = {Advanced Materials Interfaces},

volume = {9},

number = {21},

pages = {2200582},

abstract = {Abstract Disordered and porous metal oxides are promising earth-abundant and cost-effective alternatives to noble-metal electrocatalysts. Herein, nonsaturated oxidation in plasma-enhanced atomic layer deposition is leveraged to tune the structural, mechanical, and optical properties of biphasic cobalt hydroxide films, thereby tailoring their catalytic activities and chemical stabilities. Short oxygen plasma exposure times and low plasma powers incompletely oxidize the cobaltocene precursor to Co(OH)2 and result in carbon impurity incorporation. These Co(OH)2 films are highly porous and catalytically active, but their electrochemical stability is impacted by poor substrate adhesion. In contrast, long exposure times and high powers completely oxidize the precursor to Co3O4, reduce the carbon incorporation, and improve the crystallinity. While the Co3O4 films have high electrochemical stability, they are characterized by low oxygen evolution reaction activity. To overcome these competing properties, the established relation between deposition parameters and functional film properties is applied to design bilayer films exhibiting simultaneously improved electrochemical performance and chemical stability. The bilayer films combine a highly active Co(OH)2 surface with a stable Co3O4 interface layer. These coatings exhibit minimal light absorption, thus making them suitable as protective catalytic layers on semiconductor light absorbers for application in photoelectrochemical devices.},

keywords = {Foundry Inorganic, Solid-Liquid},

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 = {Foundry Inorganic, Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Understanding Carotenoid Dynamics via the Vibronic Energy Relaxation Approach},

author = {V \v{S}ebel\'{i}k and C D P Duffy and E Keil and T Pol\'{i}vka and J Hauer},

url = {https://doi.org/10.1021/acs.jpcb.2c00996},

doi = {10.1021/acs.jpcb.2c00996},

issn = {1520-6106},

year  = {2022},

date = {2022-05-24},

journal = {The Journal of Physical Chemistry B},

abstract = {Carotenoids are an integral part of natural photosynthetic complexes, with tasks ranging from light harvesting to photoprotection. Their underlying energy deactivation network of optically dark and bright excited states is extremely efficient: after excitation of light with up to 2.5 eV of photon energy, the system relaxes back to ground state on a time scale of a few picoseconds. In this article, we summarize how a model based on the vibrational energy relaxation approach (VERA) explains the main characteristics of relaxation dynamics after one-photon excitation with special emphasis on the so-called S* state. Lineshapes after two-photon excitation are beyond the current model of VERA. We outline this future line of research in our article. In terms of experimental method development, we discuss which techniques are needed to better describe energy dissipation effects in carotenoids and within the first solvation shell.},

keywords = {Foundry Inorganic, Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Capabilities and limitations of rotating disk electrodes versus membrane electrode assemblies in the investigation of electrocatalysts},

author = {T Lazaridis and B M St\"{u}hmeier and H A Gasteiger and H A El-Sayed},

url = {https://doi.org/10.1038/s41929-022-00776-5},

doi = {10.1038/s41929-022-00776-5},

issn = {2520-1158},

year  = {2022},

date = {2022-05-23},

journal = {Nature Catalysis},

volume = {5},

number = {5},

pages = {363-373},

abstract = {Cost-competitive fuel cells and water electrolysers require highly efficient electrocatalysts for the respective reactions of hydrogen oxidation and evolution, and oxygen evolution and reduction. Electrocatalyst activity and durability are commonly assessed using rotating disk electrodes (RDEs) or membrane electrode assemblies (MEAs). RDEs provide a quick and widely accessible testing tool, whereas MEA testing is more complex but closely resembles the actual application. Although both experimental set-ups allow investigation of the same reactions, there are scientific questions that cannot be answered by the RDE technique. In this Perspective, we scrutinize protocols widely used to determine the activity and durability of electrocatalysts, and highlight discrepancies in the results obtained using RDEs and MEAs. We discuss where the use of RDEs is appropriate and, conversely, where it leads to erroneous interpretations. Ultimately, we show that many of the current challenges for hydrogen and oxygen electrocatalysts require MEA testing and advocate for its greater adoption in the early stages of electrocatalyst development.},

keywords = {Foundry Inorganic, Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Controlling Plasmonic Chemistry Pathways through Specific Ion Effects},

author = {A Stefancu and L Nan and L Zhu and V Chiș and I Bald and M Liu and N Leopold and S A Maier and E Cortes},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/adom.202200397},

doi = {https://doi.org/10.1002/adom.202200397},

issn = {2195-1071},

year  = {2022},

date = {2022-05-11},

journal = {Advanced Optical Materials},

volume = {n/a},

number = {n/a},

pages = {2200397},

abstract = {Abstract Plasmon-driven dehalogenation of brominated purines has been recently explored as a model system to understand fundamental aspects of plasmon-assisted chemical reactions. Here, it is shown that divalent Ca2+ ions strongly bridge the adsorption of bromoadenine (Br-Ade) to Ag surfaces. Such ion-mediated binding increases the molecule's adsorption energy leading to an overlap of the metal energy states and the molecular states, enabling the chemical interface damping (CID) of the plasmon modes of the Ag nanostructures (i.e., direct electron transfer from the metal to Br-Ade). Consequently, the conversion of Br-Ade to adenine almost doubles following the addition of Ca2+. These experimental results, supported by theoretical calculations of the local density of states of the Ag/Br-Ade complex, indicate a change of the charge transfer pathway driving the dehalogenation reaction, from Landau damping (in the lack of Ca2+ ions) to CID (after the addition of Ca2+). The results show that the surface dynamics of chemical species (including water molecules) play an essential role in charge transfer at plasmonic interfaces and cannot be ignored. It is envisioned that these results will help in designing more efficient nanoreactors, harnessing the full potential of plasmon-assisted chemistry.},

keywords = {Molecularly-Functionalized, Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Spatially Resolved Electrochemical Impedance Spectroscopy of Automotive PEM Fuel Cells},

author = {A S Bandarenka and F Haimerl and J P Sabawa and T A Dao},

url = {https://chemistry-europe.onlinelibrary.wiley.com/doi/abs/10.1002/celc.202200069},

doi = {https://doi.org/10.1002/celc.202200069},

issn = {2196-0216},

year  = {2022},

date = {2022-04-13},

urldate = {2022-04-13},

journal = {ChemElectroChem},

volume = {n/a},

number = {n/a},

abstract = {Fuel cell electric vehicles (FCEVs), which use polymer electrolyte membrane fuel cells (PEMFCs), provide a prospect to add to a future mobility. However, an in-depth understanding of degradation mechanisms and contributions to performance losses is needed to commercialize FCEVs further. Previous PEMFC degradation research has focused on global indicators of the cell condition. Failure occurs typically due to inhomogeneities in operation, leading to localized regions of high degradation rates. Here, we present the results of a comprehensive study of spatial distributions of essential PEMFC parameters using electrochemical impedance spectroscopy across the cell surface of automotive-size fuel cells with an active area of 285cm2. In particular, the results reveal increasing mass transport problems with increasing distance from the air inlet and a tendency of lower proton resistances in the center of the cell. One hundred twenty realistic freeze-start cycles degenerated the cell performance drastically. The outer cell regions, subject to the lowest temperatures, showed the most substantial degradation rates, partly compensated by central cell regions with slightly higher temperatures. These findings bridge the gap between simulation and experiment and provide valuable insights for future fuel cell design and operating strategies.},

keywords = {Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Selectivity Trends and Role of Adsorbate-Adsorbate Interactions in CO Hydrogenation on Rhodium Catalysts},

author = {M Deimel and H Prats and M Seibt and K Reuter and M Andersen},

url = {https://arxiv.org/abs/2203.15746},

doi = {https://doi.org/10.48550/arXiv.2203.15746},

year  = {2022},

date = {2022-03-29},

journal = {arXiv preprint arXiv:2203.15746},

abstract = {Predictive-quality computational modeling of heterogeneously catalyzed reactions has emerged as an important tool for the analysis and assessment of activity and activity trends. In contrast, more subtle selectivities and selectivity trends still pose a significant challenge to prevalent microkinetic modeling approaches that typically employ a mean-field approximation (MFA). Here, we focus on CO hydrogenation on Rh catalysts with the possible products methane, acetaldehyde, ethanol and water. This reaction has already been subject to a number of experimental and theoretical studies with conflicting views on the factors controlling activity and selectivity towards the more valuable higher oxygenates. Using accelerated first-principles kinetic Monte Carlo (KMC) simulations and explicitly and systematically accounting for adsorbate-adsorbate interactions through a cluster expansion approach, we model the reaction on the low-index Rh(111) and stepped Rh(211) surfaces. We find that the Rh(111) facet is selective towards methane, while the Rh(211) facet exhibits a similar selectivity towards methane and acetaldehyde. This is consistent with the experimental selectivity observed for larger, predominantly (111)-exposing Rh nanoparticles and resolves the discrepancy to earlier first-principles MFA microkinetic work that found the Rh(111) facet to be selective towards acetaldehyde. While the latter work tried to approximately account for lateral interactions through coverage-dependent rate expressions, our analysis demonstrates that this fails to sufficiently capture concomitant correlations among the adsorbed reaction intermediates that crucially determine the overall selectivity.},

keywords = {Foundry Inorganic, Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Finding efficient catalyst designs: A high-precision method to reveal active sites},

author = {R W Haid and R M Kluge and T O Schmidt and A S Bandarenka},

url = {https://www.sciencedirect.com/science/article/pii/S2667109322001695},

doi = {https://doi.org/10.1016/j.checat.2022.03.024},

issn = {2667-1093},

year  = {2022},

date = {2022-03-16},

journal = {Chem Catalysis},

volume = {2},

number = {4},

pages = {657-659},

abstract = {Designing efficient electrocatalytic structures requires reliable guidelines. For this purpose, experimental approaches for the characterization of model electrodes in operando conditions are valuable. Reporting in Joule, Agnoli et al. showcase the determination of site-specific reaction onset potentials and Tafel slopes by using electrochemical scanning tunneling microscopy.},

keywords = {Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Dual In-situ Laser Techniques Underpin the Role of Cations in Impacting Electrocatalysts},

author = {S Hou and L Xu and X Ding and R M Kluge and T K Sarpey and R W Haid and B Garlyyev and S Mukherjee and J Warnan and M Koch and S Zhang and W Li and A S Bandarenka and R A Fischer},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/anie.202201610},

doi = {https://doi.org/10.1002/anie.202201610},

issn = {1433-7851},

year  = {2022},

date = {2022-03-10},

journal = {Angewandte Chemie International Edition},

volume = {n/a},

number = {n/a},

abstract = {Understanding the electrode/electrolyte interface is crucial for optimizing electrocatalytic performances. Here, we demonstrate that the nature of alkali metal cations can profoundly impact the oxygen evolution activity of surface-mounted metal-organic framework (SURMOF) derived electrocatalysts, which are based on NiFe(OOH). In-situ Raman spectroscopy results show that Raman shifts of the Ni-O bending vibration are inversely proportional to the mass activities from Cs+ to Li+. Particularly, a laser-induced current transient technique was introduced to study the cation-dependent electric double layer properties and their effects on the activity. The catalytic trend appeared to be closely related to the potential of maximum entropy of the system, suggesting a strong cation impact on the interfacial water layer structure. Our results highlight how the electrolyte composition can be used to maximize the performance of SURMOF derivatives toward electrochemical water splitting.},

keywords = {Foundry Inorganic, Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Solvent Tuning of the Active Layer Morphology of Non-Fullerene Based Organic Solar Cells},

author = {S Grott and A Kotobi and L K Reb and C L Weindl and R Guo and S Yin and K S Wienhold and W Chen and T Ameri and M Schwartzkopf and S V Roth and P M\"{u}ller-Buschbaum},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/solr.202101084},

doi = {https://doi.org/10.1002/solr.202101084},

issn = {2367-198X},

year  = {2022},

date = {2022-02-12},

journal = {Solar RRL},

volume = {n/a},

number = {n/a},

pages = {2101084},

abstract = {Non-fullerene acceptor (NFA)-based organic solar cells have made tremendous progress in recent years. For the neat NFA system PBDB-T:ITIC, the film morphology and crystallinity are tailored by the choice of the solvent used for spin coating the active layers. Three different chlorinated solvents, chlorobenzene (CB), chloroform, and dichlorobenzene, are compared and the obtained active layer morphology is correlated with the optoelectronic properties and the device performance. The small domain sizes in the case of CB are most beneficial for the device performance, whereas the largest number or size of face-on PBDB-T crystallites is not causing the highest power conversion efficiencies (PCEs). In addition, when using CB, the number of edge-on crystallites is highest and the distances between neighboring domains are small. The smoothest blend films are realized with CB, which exhibit correlated roughness with their substrates and no large aggregates have formed in these blend films. Thus, CB offers the best way to balance the aggregation and crystallization kinetics in the active layer and enables the highest PCE values.},

keywords = {Foundry Organic, Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Accelerating CO2 Electroreduction to Multicarbon Products via Synergistic Electric\textendashThermal Field on Copper Nanoneedles},

author = {B Yang and K Liu and H Li and C Liu and J Fu and H Li and J E Huang and P Ou and T Alkayyali and C Cai and Y Duan and H Liu and P An and N Zhang and W Li and X Qiu and C Jia and J Hu and L Chai and Z Lin and Y Gao and M Miyauchi and E Cort\'{e}s and S A Maier and M Liu},

url = {https://doi.org/10.1021/jacs.1c11253},

doi = {10.1021/jacs.1c11253},

issn = {0002-7863},

year  = {2022},

date = {2022-02-03},

urldate = {2022-02-03},

journal = {Journal of the American Chemical Society},

abstract = {Electrochemical CO2 reduction is a promising way to mitigate CO2 emissions and close the anthropogenic carbon cycle. Among products from CO2RR, multicarbon chemicals, such as ethylene and ethanol with high energy density, are more valuable. However, the selectivity and reaction rate of C2 production are unsatisfactory due to the sluggish thermodynamics and kinetics of C\textendashC coupling. The electric field and thermal field have been studied and utilized to promote catalytic reactions, as they can regulate the thermodynamic and kinetic barriers of reactions. Either raising the potential or heating the electrolyte can enhance C\textendashC coupling, but these come at the cost of increasing side reactions, such as the hydrogen evolution reaction. Here, we present a generic strategy to enhance the local electric field and temperature simultaneously and dramatically improve the electric\textendashthermal synergy desired in electrocatalysis. A conformal coating of ∼5 nm of polytetrafluoroethylene significantly improves the catalytic ability of copper nanoneedles (∼7-fold electric field and ∼40 K temperature enhancement at the tips compared with bare copper nanoneedles experimentally), resulting in an improved C2 Faradaic efficiency of over 86% at a partial current density of more than 250 mA cm\textendash2 and a record-high C2 turnover frequency of 11.5 ± 0.3 s\textendash1 Cu site\textendash1. Combined with its low cost and scalability, the electric\textendashthermal strategy for a state-of-the-art catalyst not only offers new insight into improving activity and selectivity of value-added C2 products as we demonstrated but also inspires advances in efficiency and/or selectivity of other valuable electro-/photocatalysis such as hydrogen evolution, nitrogen reduction, and hydrogen peroxide electrosynthesis.},

keywords = {Foundry Inorganic, Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Hybrid Plasmonic Nanomaterials for Hydrogen Generation and Carbon Dioxide Reduction},

author = {S Ezendam and M Herran and L Nan and C Gruber and Y Kang and F Gr\"{o}bmeyer and R Lin and J Gargiulo and A Sousa-Castillo and E Cort\'{e}s},

url = {https://doi.org/10.1021/acsenergylett.1c02241},

doi = {10.1021/acsenergylett.1c02241},

year  = {2022},

date = {2022-01-24},

urldate = {2022-01-24},

journal = {ACS Energy Letters},

pages = {778-815},

abstract = {The successful development of artificial photosynthesis requires finding new materials able to efficiently harvest sunlight and catalyze hydrogen generation and carbon dioxide reduction reactions. Plasmonic nanoparticles are promising candidates for these tasks, due to their ability to confine solar energy into molecular regions. Here, we review recent developments in hybrid plasmonic photocatalysis, including the combination of plasmonic nanomaterials with catalytic metals, semiconductors, perovskites, 2D materials, metal\textendashorganic frameworks, and electrochemical cells. We perform a quantitative comparison of the demonstrated activity and selectivity of these materials for solar fuel generation in the liquid phase. In this way, we critically assess the state-of-the-art of hybrid plasmonic photocatalysts for solar fuel production, allowing its benchmarking against other existing heterogeneous catalysts. Our analysis allows the identification of the best performing plasmonic systems, useful to design a new generation of plasmonic catalysts.},

keywords = {Molecularly-Functionalized, Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Electrolyte Effects on the Stabilization of Prussian Blue Analogue Electrodes in Aqueous Sodium-Ion Batteries},

author = {X Lamprecht and F Speck and P Marzak and S Cherevko and A S Bandarenka},

url = {https://doi.org/10.1021/acsami.1c21219},

doi = {10.1021/acsami.1c21219},

issn = {1944-8244},

year  = {2022},

date = {2022-01-06},

urldate = {2022-01-06},

journal = {ACS Applied Materials \& Interfaces},

volume = {14},

pages = {3515-3525},

abstract = {Aqueous sodium-ion batteries based on Prussian Blue Analogues (PBA) are considered as promising and scalable candidates for stationary energy storage systems, where longevity and cycling stability are assigned utmost importance to maintain economic viability. Although degradation due to active material dissolution is a common issue of battery electrodes, it is hardly observable directly due to a lack of in operando techniques, making it challenging to optimize the performance of electrodes. By operating Na2Ni[Fe(CN)6] and Na2Co[Fe(CN)6] model electrodes in a flow-cell setup connected to an inductively coupled plasma mass spectrometer, in this work, the dynamics of constituent transition-metal dissolution during the charge\textendashdischarge cycles was monitored in real time. At neutral pHs, the extraction of nickel and cobalt was found to drive the degradation process during charge\textendashdischarge cycles. It was also found that the nature of anions present in the electrolytes has a significant impact on the degradation rate, determining the order ClO4\textendash \> NO3\textendash \> Cl\textendash \> SO42\textendash with decreasing stability from the perchlorate to sulfate electrolytes. It is proposed that the dissolution process is initiated by detrimental specific adsorption of anions during the electrode oxidation, therefore scaling with their respective chemisorption affinity. This study involves an entire comparison of the effectiveness of common stabilization strategies for PBAs under very fast (dis)charging conditions at 300C, emphasizing the superiority of highly concentrated NaClO4 with almost no capacity loss after 10 000 cycles for Na2Ni[Fe(CN)6].},

keywords = {Foundry Inorganic, Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Exploration of the Electrical Double Layer Structure: Influence of Electrolyte Components on the Double Layer Capacitance and Potential of Maximum Entropy},

author = {R W Haid and X Ding and T K Sarpey and A S Bandarenka and B Garlyyev},

url = {https://www.sciencedirect.com/science/article/pii/S2451910321001964},

doi = {https://doi.org/10.1016/j.coelec.2021.100882},

issn = {2451-9103},

year  = {2022},

date = {2022-01-01},

urldate = {2021-11-17},

journal = {Current Opinion in Electrochemistry},

volume = {32},

pages = {100882},

abstract = {Understanding the electrical double layer structure is of paramount importance for designing efficient electrochemical energy conversion systems. Under this aspect, this short review explores the influence of the electrolyte on parameters such as the double layer capacitance and the potential of maximum entropy. Investigation of those parameters offers a deeper understanding on how the interfacial structure changes near reaction conditions. As a consequence, one can tune the catalyst activity by creating a more favorable environment in the electrolyte. The aim of this short review is to provide the reader with recent studies examining the electrode/electrolyte interface from experimental and theoretical standpoints.},

keywords = {Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Prospects of Using the Laser-Induced Temperature Jump Techniques for Characterisation of Electrochemical Systems},

author = {X Ding and T K Sarpey and S Hou and B Garlyyev and W Li and R A Fischer and A S Bandarenka},

url = {https://chemistry-europe.onlinelibrary.wiley.com/doi/abs/10.1002/celc.202101175},

doi = {https://doi.org/10.1002/celc.202101175},

issn = {2196-0216},

year  = {2022},

date = {2022-01-01},

urldate = {2022-01-01},

journal = {ChemElectroChem},

volume = {9},

number = {4},

pages = {e20210117},

abstract = {Abstract Understanding the processes, phenomena, and mechanisms occurring at the electrode/electrolyte interface is a prerequisite and significant for optimizing electrochemical systems. To this end, the advent of sub-microsecond laser pulses has paved the way and eased the investigations of the electrochemical interface (e. g., electric double layer), which hitherto is difficult. The laser-induced current transient (LICT) and laser-induced potential transient (LIPT) techniques have proven to be valuable and unique tools for measuring key parameters of the electrified interface, such as the potential of maximum entropy (PME) and the potential of zero charge (PZC). Herein, we present a summary of studies performed in recent years using laser-induced temperature jump techniques. The relation between the PME/PZC and the electrocatalytic properties of various electrochemical interfaces are particularly highlighted. Special attention is given to its applications in investigating different systems and analyzing the influence of the electrolyte components, electrode composition and structure on the PME/PZC and various electrochemical processes. Moreover, possible applications of the LICT/LIPT techniques to investigate the interfacial properties of a myriad of materials, including surface-mounted metal-organic frameworks and metal oxides, are elaborated.},

keywords = {Foundry Inorganic, Solid-Liquid},

pubstate = {published},

tppubtype = {article}

}