1344.
A Gouder, B V Lotsch
Optoionics - Controlling ions with light☆ Artikel
In: Solid State Ionics, Bd. 431, 2025, ISSN: 0167-2738.
@article{nokey,
title = {Optoionics - Controlling ions with light☆},
author = {A Gouder and B V Lotsch},
url = {\<Go to ISI\>://WOS:001576659000001},
doi = {10.1016/j.ssi.2025.117018},
issn = {0167-2738},
year = {2025},
date = {2025-11-01},
journal = {Solid State Ionics},
volume = {431},
abstract = {Optoionics has recently emerged at the intersection of optoelectronics and solid state ionics, triggered by fundamental work on light-induced ionic conductivity enhancement in methylammonium lead iodide (MAPI). This perspective traces the evolution of optoionics from early 20th century studies on photoionics to contemporary research, elucidating the semantic nuances and historical development of light-ion interactions. We follow the first observations such as copper photoionization and subsequent conceptual extensions such as molecular photoionics and photo-ionic cells, leading on to the current definition and understanding of optoionics. We then proceed to apply this understanding on light-ion interactions in carbon nitrides, distinguishing between intrinsic and extrinsic optoionic effects depending on whether one or more distinct phases are involved. This nuanced understanding is essential for the design of optoionic devices that exploit light-ion interactions to couple light harvesting and electrochemical energy storage. Finally, we provide an outlook on emerging optoionic devices at the intersection of energy conversion and storage and discuss smart circuit elements that integrate optoionic principles for advanced technological applications.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Optoionics has recently emerged at the intersection of optoelectronics and solid state ionics, triggered by fundamental work on light-induced ionic conductivity enhancement in methylammonium lead iodide (MAPI). This perspective traces the evolution of optoionics from early 20th century studies on photoionics to contemporary research, elucidating the semantic nuances and historical development of light-ion interactions. We follow the first observations such as copper photoionization and subsequent conceptual extensions such as molecular photoionics and photo-ionic cells, leading on to the current definition and understanding of optoionics. We then proceed to apply this understanding on light-ion interactions in carbon nitrides, distinguishing between intrinsic and extrinsic optoionic effects depending on whether one or more distinct phases are involved. This nuanced understanding is essential for the design of optoionic devices that exploit light-ion interactions to couple light harvesting and electrochemical energy storage. Finally, we provide an outlook on emerging optoionic devices at the intersection of energy conversion and storage and discuss smart circuit elements that integrate optoionic principles for advanced technological applications.
1343.
J Reich, M Soltanmohammadi, V Vonk, S Kaiser, U Heiz, A Stierle, F Esch, B J Lechner
Steering Pt Cluster Dimensionality via the Surface Oxidation State of CeO2(111) Thin Films Artikel
In: Acs Catalysis, 2025, ISSN: 2155-5435.
@article{nokey,
title = {Steering Pt Cluster Dimensionality via the Surface Oxidation State of CeO2(111) Thin Films},
author = {J Reich and M Soltanmohammadi and V Vonk and S Kaiser and U Heiz and A Stierle and F Esch and B J Lechner},
url = {\<Go to ISI\>://WOS:001598368800001},
doi = {10.1021/acscatal.5c05570},
issn = {2155-5435},
year = {2025},
date = {2025-10-22},
journal = {Acs Catalysis},
abstract = {Ceria has recently regained attention in catalysis research, thanks to its ability to reversibly form and redisperse supported, catalytically active Pt clusters through control of its surface morphology and oxidation state. In the present article, we systematically and independently tune these parameters during CeO2(111) film synthesis to investigate their influence on the dimensionality (2D vs 3D) and sintering behavior of size-selected Pt20 clusters. We present recipes for atomically flat CeO2(111) islands and closed films with a thickness of up to 18 monolayers, grown on Rh(111), and characterize them by means of scanning tunneling microscopy (STM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and low-energy electron diffraction (LEED). Remarkably, XRD and LEED reveal an epitaxially grown, crystalline, and relaxed closed film of a single domain, with cube-on-cube alignment. Bulk or exclusive surface reduction is achieved by ultra-high vacuum annealing or room temperature CH3OH dosing and annealing cycles, respectively. The methanol procedure forms oxygen vacancies only in the surface without reducing the deeper layers of the film or introducing roughening. From STM images, we extract detailed height distributions and coverages of Pt20 clusters and find that Ostwald ripening already sets in around 600 K on both, fully oxidized and surface-reduced ceria, without any indication for cluster diffusion and coalescence. XPS shows that atom detachment during sintering leads to the intermediate formation of Pt2+ species on oxidized ceria, in line with the redispersed single atoms at step edges observed in the literature. Strikingly, while the clusters appear similarly upon deposition on both supports, they show a distinct temperature-dependent dimensionality upon annealing: Exclusively 3D clusters form on the oxidized support, while most clusters on the reduced support adopt a flat, 2D geometry upon sintering, stabilized by O vacancies.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Ceria has recently regained attention in catalysis research, thanks to its ability to reversibly form and redisperse supported, catalytically active Pt clusters through control of its surface morphology and oxidation state. In the present article, we systematically and independently tune these parameters during CeO2(111) film synthesis to investigate their influence on the dimensionality (2D vs 3D) and sintering behavior of size-selected Pt20 clusters. We present recipes for atomically flat CeO2(111) islands and closed films with a thickness of up to 18 monolayers, grown on Rh(111), and characterize them by means of scanning tunneling microscopy (STM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and low-energy electron diffraction (LEED). Remarkably, XRD and LEED reveal an epitaxially grown, crystalline, and relaxed closed film of a single domain, with cube-on-cube alignment. Bulk or exclusive surface reduction is achieved by ultra-high vacuum annealing or room temperature CH3OH dosing and annealing cycles, respectively. The methanol procedure forms oxygen vacancies only in the surface without reducing the deeper layers of the film or introducing roughening. From STM images, we extract detailed height distributions and coverages of Pt20 clusters and find that Ostwald ripening already sets in around 600 K on both, fully oxidized and surface-reduced ceria, without any indication for cluster diffusion and coalescence. XPS shows that atom detachment during sintering leads to the intermediate formation of Pt2+ species on oxidized ceria, in line with the redispersed single atoms at step edges observed in the literature. Strikingly, while the clusters appear similarly upon deposition on both supports, they show a distinct temperature-dependent dimensionality upon annealing: Exclusively 3D clusters form on the oxidized support, while most clusters on the reduced support adopt a flat, 2D geometry upon sintering, stabilized by O vacancies.
1342.
A F Harper, S S Köcher, K Reuter, C Scheurer
In: Journal of Materials Chemistry A, Bd. 13, Nr. 41, S. 35389-35399, 2025, ISSN: 2050-7488.
@article{nokey,
title = {Performance metrics for tensorial learning: prediction of Li4Ti5O12 nuclear magnetic resonance observables at experimental accuracy},
author = {A F Harper and S S K\"{o}cher and K Reuter and C Scheurer},
url = {\<Go to ISI\>://WOS:001582683500001},
doi = {10.1039/d5ta05090a},
issn = {2050-7488},
year = {2025},
date = {2025-10-21},
journal = {Journal of Materials Chemistry A},
volume = {13},
number = {41},
pages = {35389-35399},
abstract = {Predicting observable quantities from first principles calculations is the next frontier within the field of machine learning (ML) for materials modelling. While ML models have shown success for the prediction of scalar properties such as energetics or band gaps, models and performance metrics for the learning of higher order tensor-based observables have not yet been formalized. ML models for experimental observables, including tensorial quantities, are essential for exploiting the full potential of the paradigm shift enabled by machine learned interatomic potentials by mapping the structure-property relationship in an equally efficient way. In this work, we establish performance metrics for accurately predicting the electric field gradient tensor (EFG) underlying nuclear magnetic resonance (NMR) spectroscopy. We further demonstrate the superiority of a tensorial learning approach that fully encodes the corresponding symmetries over a separate scalar learning of individual tensor-derived observables. To this end we establish an extensive EFG dataset representative of real experimental applications and develop performance metrics for model evaluation which directly focus on the targeted NMR observables. Finally, by leveraging the computational efficiency of the ML method employed, we predict quadrupolar observables for 1512 atom models of Li4Ti5O12, a high performance Li-ion battery anode material, which is capable of accurately distinguishing local atomic environments via their NMR observables. This workflow and dataset sets the standard for the next generation of tensorial based learning for spectroscopic observables.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Predicting observable quantities from first principles calculations is the next frontier within the field of machine learning (ML) for materials modelling. While ML models have shown success for the prediction of scalar properties such as energetics or band gaps, models and performance metrics for the learning of higher order tensor-based observables have not yet been formalized. ML models for experimental observables, including tensorial quantities, are essential for exploiting the full potential of the paradigm shift enabled by machine learned interatomic potentials by mapping the structure-property relationship in an equally efficient way. In this work, we establish performance metrics for accurately predicting the electric field gradient tensor (EFG) underlying nuclear magnetic resonance (NMR) spectroscopy. We further demonstrate the superiority of a tensorial learning approach that fully encodes the corresponding symmetries over a separate scalar learning of individual tensor-derived observables. To this end we establish an extensive EFG dataset representative of real experimental applications and develop performance metrics for model evaluation which directly focus on the targeted NMR observables. Finally, by leveraging the computational efficiency of the ML method employed, we predict quadrupolar observables for 1512 atom models of Li4Ti5O12, a high performance Li-ion battery anode material, which is capable of accurately distinguishing local atomic environments via their NMR observables. This workflow and dataset sets the standard for the next generation of tensorial based learning for spectroscopic observables.
1341.
R Babu, H Y Xu, B Covelo, I Pérez-Juste, J E Heger, N Solhtalab, Z L Li, L F Zhong, X W Hu, F Deschler, P Müller-Buschbaum, X Jiang, S Gómez-Graña, L Polavarapu
Chiral Molecules Induce Enantiomorphic Lattice Helicity in Chiral 0D Tin Bromide Crystals Artikel
In: Angewandte Chemie-International Edition, Bd. 64, Nr. 43, 2025.
@article{nokey,
title = {Chiral Molecules Induce Enantiomorphic Lattice Helicity in Chiral 0D Tin Bromide Crystals},
author = {R Babu and H Y Xu and B Covelo and I P\'{e}rez-Juste and J E Heger and N Solhtalab and Z L Li and L F Zhong and X W Hu and F Deschler and P M\"{u}ller-Buschbaum and X Jiang and S G\'{o}mez-Gra\~{n}a and L Polavarapu},
url = {\<Go to ISI\>://WOS:001560736100001},
doi = {10.1002/anie.202510842},
year = {2025},
date = {2025-10-20},
journal = {Angewandte Chemie-International Edition},
volume = {64},
number = {43},
abstract = {Chiral organic-inorganic hybrid metal halides have emerged as a promising class of materials for spin-controlled optical and optoelectronic effects and related applications. Chiral hybrid metal halides generally crystallize in non-helical space groups. Herein, we report the discovery of zero-dimensional (0D) chiral (R/S-MBA)2SnBr6 (MBA: methylbenzylammonium cation) single crystals with enantiomorphic lattice helicity. The S-enantiomer of the chiral molecule induces right-handed helicity with the P61 space group (right-handed, P-helix), while the R-enantiomer induces right-handed helicity with the P65 space group (left-handed, M-helix). The chiral molecules induce the helical twist of inorganic units in the lattice through N \& horbar;H\<middle dot\>\<middle dot\>\<middle dot\>Br and C \& horbar;H\<middle dot\>\<middle dot\>\<middle dot\>pi interactions. Density functional theory (DFT) calculations indicate that the strong electronic coupling between chiral molecules and SnBr6 2- subunits is responsible for the generation of chirality. The chiral crystals exhibit circular dicroism (CD) spectra with a high dissymmetry factor (g CD) of 3.5 x 10- 2 and no Cotton effect, maintaining the same CD sign throughout the spectrum. In addition, they exhibit broadband second harmonic generation (SHG) over a broad excitation range, with a g CP-SHG up to 0.44. Furthermore, we find that the alloying of Sn with Pb leads to a change in dimensionality from 0D to non-helical 1D structures. These crystals with helical lattices and interesting CD responses are expected to open new avenues for spin-controlled applications.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Chiral organic-inorganic hybrid metal halides have emerged as a promising class of materials for spin-controlled optical and optoelectronic effects and related applications. Chiral hybrid metal halides generally crystallize in non-helical space groups. Herein, we report the discovery of zero-dimensional (0D) chiral (R/S-MBA)2SnBr6 (MBA: methylbenzylammonium cation) single crystals with enantiomorphic lattice helicity. The S-enantiomer of the chiral molecule induces right-handed helicity with the P61 space group (right-handed, P-helix), while the R-enantiomer induces right-handed helicity with the P65 space group (left-handed, M-helix). The chiral molecules induce the helical twist of inorganic units in the lattice through N & horbar;H<middle dot><middle dot><middle dot>Br and C & horbar;H<middle dot><middle dot><middle dot>pi interactions. Density functional theory (DFT) calculations indicate that the strong electronic coupling between chiral molecules and SnBr6 2- subunits is responsible for the generation of chirality. The chiral crystals exhibit circular dicroism (CD) spectra with a high dissymmetry factor (g CD) of 3.5 x 10- 2 and no Cotton effect, maintaining the same CD sign throughout the spectrum. In addition, they exhibit broadband second harmonic generation (SHG) over a broad excitation range, with a g CP-SHG up to 0.44. Furthermore, we find that the alloying of Sn with Pb leads to a change in dimensionality from 0D to non-helical 1D structures. These crystals with helical lattices and interesting CD responses are expected to open new avenues for spin-controlled applications.
1340.
H Y Shen, N Bogo, C J Stein, M Head-Gordon
In: Journal of Chemical Theory and Computation, Bd. 21, Nr. 19, S. 9525-9537, 2025, ISSN: 1549-9618.
@article{nokey,
title = {Understanding Electronic Excitations Between Single Determinants with Occupied-Virtual Orbitals for Chemical Valence},
author = {H Y Shen and N Bogo and C J Stein and M Head-Gordon},
url = {\<Go to ISI\>://WOS:001571614800001},
doi = {10.1021/acs.jctc.5c01029},
issn = {1549-9618},
year = {2025},
date = {2025-10-14},
journal = {Journal of Chemical Theory and Computation},
volume = {21},
number = {19},
pages = {9525-9537},
abstract = {One approach to calculating electronic excited states treats both ground and excited states as single determinants, either by direct optimization or with the aid of constraints. In this work, we extend the theory of occupied-virtual orbitals for chemical valence (OVOCV) to analyze the orbital character of excitations computed in this way. An intermediate frozen state that is polarization-free is introduced to cleanly separate the primary excitation from the accompanying orbital relaxation of spectator orbitals. A variety of chemical examples are reported using the OVOCV excitation analysis on orbital-optimized density functional theory (OO-DFT) calculations, including charge-transfer excitations, core excitations and singly and doubly excited valence states. Orbital relaxation effects are typically collective, and can be as large as 4-5 eV (with roughly 0.1 e - promoted) in charge transfer states, and even larger in core excited states. OVOCV analysis differs from natural transition orbital (NTO) analysis; we show that direct use of NTOs can largely obscure the role of orbital relaxation in favor of the primary excitation.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
One approach to calculating electronic excited states treats both ground and excited states as single determinants, either by direct optimization or with the aid of constraints. In this work, we extend the theory of occupied-virtual orbitals for chemical valence (OVOCV) to analyze the orbital character of excitations computed in this way. An intermediate frozen state that is polarization-free is introduced to cleanly separate the primary excitation from the accompanying orbital relaxation of spectator orbitals. A variety of chemical examples are reported using the OVOCV excitation analysis on orbital-optimized density functional theory (OO-DFT) calculations, including charge-transfer excitations, core excitations and singly and doubly excited valence states. Orbital relaxation effects are typically collective, and can be as large as 4-5 eV (with roughly 0.1 e - promoted) in charge transfer states, and even larger in core excited states. OVOCV analysis differs from natural transition orbital (NTO) analysis; we show that direct use of NTOs can largely obscure the role of orbital relaxation in favor of the primary excitation.
1339.
S D Wang, M Gösswein, G Tullii, C Marzuoli, M R Antognazza, A Gagliardi
In: Advanced Materials Interfaces, 2025, ISSN: 2196-7350.
@article{nokey,
title = {A Kinetic Monte Carlo Model to Understand Limiting Regimes of Photocurrent and Interfacial Charge Transfer in Organic Semiconductor-Electrolyte Interfaces},
author = {S D Wang and M G\"{o}sswein and G Tullii and C Marzuoli and M R Antognazza and A Gagliardi},
url = {\<Go to ISI\>://WOS:001592409000001},
doi = {10.1002/admi.202500343},
issn = {2196-7350},
year = {2025},
date = {2025-10-13},
journal = {Advanced Materials Interfaces},
abstract = {Organic semiconductor-electrolyte interfaces enable a wide range of applications, spanning photoelectrochemistry, energy conversion, and bioelectronics. Predictive modeling of the complex interplay among light-charge conversion, charge transport, and redox reaction kinetics is essential for advancing specific applications, but an in-depth understanding of the polymer/water interfaces (PWIs) under optical excitation remains incomplete. This work presents a multiphysics kinetic Monte Carlo simulation to quantitatively reproduce the photoelectrochemical behavior of a prototypical PWI between poly(3-hexylthiophene) (P3HT) and phosphate-buffered saline. The simulation model enables nanometer-scale resolution of space-charge regions and cross-interface electron-solute interactions. The study reveals that the electrochemical current can be limited by the transport of minority charge carriers in the organic electrode when light is absorbed from the opposite side of the PWI; moreover, it can be further limited by the inverted Marcus region in the P3HT/O-2 system. Overall, results demonstrate that Marcus-Gerischer theory is inadequate for describing the current-potential curves, necessitating the particle-based simulations with molecular Marcus theory. By bridging microscopic kinetics with device-level performance, this work deepens the mechanistic understanding of interfacial charge transfer and current flow across the PWI, providing valuable design principles for next-generation biohybrid devices.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Organic semiconductor-electrolyte interfaces enable a wide range of applications, spanning photoelectrochemistry, energy conversion, and bioelectronics. Predictive modeling of the complex interplay among light-charge conversion, charge transport, and redox reaction kinetics is essential for advancing specific applications, but an in-depth understanding of the polymer/water interfaces (PWIs) under optical excitation remains incomplete. This work presents a multiphysics kinetic Monte Carlo simulation to quantitatively reproduce the photoelectrochemical behavior of a prototypical PWI between poly(3-hexylthiophene) (P3HT) and phosphate-buffered saline. The simulation model enables nanometer-scale resolution of space-charge regions and cross-interface electron-solute interactions. The study reveals that the electrochemical current can be limited by the transport of minority charge carriers in the organic electrode when light is absorbed from the opposite side of the PWI; moreover, it can be further limited by the inverted Marcus region in the P3HT/O-2 system. Overall, results demonstrate that Marcus-Gerischer theory is inadequate for describing the current-potential curves, necessitating the particle-based simulations with molecular Marcus theory. By bridging microscopic kinetics with device-level performance, this work deepens the mechanistic understanding of interfacial charge transfer and current flow across the PWI, providing valuable design principles for next-generation biohybrid devices.
1338.
F C Apfelbeck, G E Wittmann, M P Le Dû, L Y Y Cheng, Y X Liang, Y Y Yan, A Davydok, C Krywka, P Müller-Buschbaum
In: Nature Communications, Bd. 16, Nr. 1, 2025.
@article{nokey,
title = {Local crystallization inside the polymer electrolyte for lithium metal batteries observed by operando nanofocus WAXS},
author = {F C Apfelbeck and G E Wittmann and M P Le D\^{u} and L Y Y Cheng and Y X Liang and Y Y Yan and A Davydok and C Krywka and P M\"{u}ller-Buschbaum},
url = {\<Go to ISI\>://WOS:001591043700035},
doi = {10.1038/s41467-025-64736-w},
year = {2025},
date = {2025-10-08},
journal = {Nature Communications},
volume = {16},
number = {1},
abstract = {The development of next-generation lithium-based batteries is accompanied by the intention to suppress the formation of dendritic lithium on the electrode, and is dominated by the picture that dendrites start to grow at the electrodes. Shifting from liquid to solid-state electrolytes, a high transference number is a quantity that promises the restraint of such parasitic side reactions. In this study, nanofocus X-ray wide-angle scattering is used to detect possible lithium-based crystallites in the polymer-based electrolyte. We perform operando scanning nanofocus wide-angle X-ray scattering on a composite gel-type polymer consisting of poly(vinylidene fluoride-co-hexafluoropropylene) and the single-ion conducting polymer poly((trifluoromethane) sulfonimide lithium styrene) in a lithium symmetric cell. We observe the occurrence and kinetics of lithium carbonate crystallites inside the electrolyte over a depth of 16 mu m during three half-cycles. Furthermore, we prove the existence of lithium hydroxide crystallites near the lithium electrode and their absence in the bulk. Importantly, we identify the growth of pure metallic lithium inside the electrolyte as a sign of lithium dendrite growth happening inside the polymer-based electrolyte and not at the electrodes. Thus, nanofocus wide-angle X-ray scattering visualizes local structure changes such as dendrite formation inside the polymer-based electrolyte despite an unchanged electrochemical performance.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The development of next-generation lithium-based batteries is accompanied by the intention to suppress the formation of dendritic lithium on the electrode, and is dominated by the picture that dendrites start to grow at the electrodes. Shifting from liquid to solid-state electrolytes, a high transference number is a quantity that promises the restraint of such parasitic side reactions. In this study, nanofocus X-ray wide-angle scattering is used to detect possible lithium-based crystallites in the polymer-based electrolyte. We perform operando scanning nanofocus wide-angle X-ray scattering on a composite gel-type polymer consisting of poly(vinylidene fluoride-co-hexafluoropropylene) and the single-ion conducting polymer poly((trifluoromethane) sulfonimide lithium styrene) in a lithium symmetric cell. We observe the occurrence and kinetics of lithium carbonate crystallites inside the electrolyte over a depth of 16 mu m during three half-cycles. Furthermore, we prove the existence of lithium hydroxide crystallites near the lithium electrode and their absence in the bulk. Importantly, we identify the growth of pure metallic lithium inside the electrolyte as a sign of lithium dendrite growth happening inside the polymer-based electrolyte and not at the electrodes. Thus, nanofocus wide-angle X-ray scattering visualizes local structure changes such as dendrite formation inside the polymer-based electrolyte despite an unchanged electrochemical performance.
1337.
M Lang, K Fykouras, M Doblinger, O Henrotte, P Muller-Buschbaum, E Cortes, J K Stolarczyk, L Leppert, Q A Akkerman
Emergence of Intrinsic One-Dimensional Excitons in Colloidal Bi13S18I2 Nanocrystals Artikel
In: Journal of Physical Chemistry Letters, Bd. 16, Nr. 39, S. 10265-10272, 2025, ISSN: 1948-7185.
@article{nokey,
title = {Emergence of Intrinsic One-Dimensional Excitons in Colloidal Bi13S18I2 Nanocrystals},
author = {M Lang and K Fykouras and M Doblinger and O Henrotte and P Muller-Buschbaum and E Cortes and J K Stolarczyk and L Leppert and Q A Akkerman},
url = {\<Go to ISI\>://WOS:001582705500001},
doi = {10.1021/acs.jpclett.5c02579},
issn = {1948-7185},
year = {2025},
date = {2025-10-02},
journal = {Journal of Physical Chemistry Letters},
volume = {16},
number = {39},
pages = {10265-10272},
abstract = {We present a synthesis method for colloidal nanocrystals exhibiting a one-dimensional Peierls-like distortion in the form of size-tunable colloidal and monodisperse Bi13S18I2 nanorods. The Bi13S18I2 nanorods exhibit an absorption onset around 1.6 eV and an excitonic transition around 1.1 eV. First-principles calculations demonstrate that this intrinsic excitonic transition originates from one-dimensional excitons localized in the Bi2+ columns formed within the Bi13S18I2 lattice. In these columns, a Peierls-like distortion results in Bi2+ dimerization and the formation of a Peierls bandgap, which is intrinsic to Bi13S18I2. This work demonstrates an exciting approach to induce excitonic properties in semiconductors without relying on traditional quantum confinement strategies, as well as opportunities to explore the spontaneous inherent symmetry breaking in nanocrystals. The Bi13S18I2 nanorods also highlight the important role of colloidal chemistry in the discovery of complex materials and their optical properties and motivate further exploration of metal chalcohalide nanocrystals.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
We present a synthesis method for colloidal nanocrystals exhibiting a one-dimensional Peierls-like distortion in the form of size-tunable colloidal and monodisperse Bi13S18I2 nanorods. The Bi13S18I2 nanorods exhibit an absorption onset around 1.6 eV and an excitonic transition around 1.1 eV. First-principles calculations demonstrate that this intrinsic excitonic transition originates from one-dimensional excitons localized in the Bi2+ columns formed within the Bi13S18I2 lattice. In these columns, a Peierls-like distortion results in Bi2+ dimerization and the formation of a Peierls bandgap, which is intrinsic to Bi13S18I2. This work demonstrates an exciting approach to induce excitonic properties in semiconductors without relying on traditional quantum confinement strategies, as well as opportunities to explore the spontaneous inherent symmetry breaking in nanocrystals. The Bi13S18I2 nanorods also highlight the important role of colloidal chemistry in the discovery of complex materials and their optical properties and motivate further exploration of metal chalcohalide nanocrystals.
1336.
G J Pan, W H Xie, S Z Liang, T Tian, S S Yin, L X Li, A Buyan-Arivjikh, J S Zhang, T Baier, Z J Xu, M Schwartzkopf, S K Vayalil, S V Roth, Y H Deng, P Müller-Buschbaum
In: Advanced Functional Materials, 2025, ISSN: 1616-301X.
@article{nokey,
title = {Kinetic Insights into Precursor-Assisted Soft Sphere Close Packing Revealed by In Situ GISAXS with Implications for Gas Sensing},
author = {G J Pan and W H Xie and S Z Liang and T Tian and S S Yin and L X Li and A Buyan-Arivjikh and J S Zhang and T Baier and Z J Xu and M Schwartzkopf and S K Vayalil and S V Roth and Y H Deng and P M\"{u}ller-Buschbaum},
url = {\<Go to ISI\>://WOS:001584801300001},
doi = {10.1002/adfm.202505935},
issn = {1616-301X},
year = {2025},
date = {2025-10-01},
journal = {Advanced Functional Materials},
abstract = {Packing of soft spheres, such as micelles, polymer-grafted particles, and microgels, enables the creation of diverse functional materials. Despite the importance of achieving precise structural control, understanding the kinetics of non-equilibrium packing in a large-scale deposition process remains challenging. This study investigates the kinetics of the precursor-assisted close packing of soft spheres using block copolymer micelles as the sphere model. Adding the inorganic precursor SnCl4 is crucial for achieving the close packing, which is versatile and provides a robust platform for tailoring mesoporous materials with tunable pore sizes. The kinetics of the close-packing process are explored by in situ grazing-incidence small-angle X-ray scattering measurements during slot-die coating. The soft crystallization process shows six distinct stages: dilute dispersion, concentrated dispersion, wet film, structuring wet film, gel film, and glassy film. The close packing develops first in the in-plane direction with rapid domain growth and then advances in the out-of-plane direction. Precursors in the interstitial voids play a key role by mitigating packing frustration and favoring face-centered cubic (FCC) ordering. The structure finally stabilizes into a well-ordered FCC structure with large domain sizes. The derived mesoporous SnO2 features semiconducting properties and enhanced pore connectivity, thus showing superior gas sensing performance toward ethanol.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Packing of soft spheres, such as micelles, polymer-grafted particles, and microgels, enables the creation of diverse functional materials. Despite the importance of achieving precise structural control, understanding the kinetics of non-equilibrium packing in a large-scale deposition process remains challenging. This study investigates the kinetics of the precursor-assisted close packing of soft spheres using block copolymer micelles as the sphere model. Adding the inorganic precursor SnCl4 is crucial for achieving the close packing, which is versatile and provides a robust platform for tailoring mesoporous materials with tunable pore sizes. The kinetics of the close-packing process are explored by in situ grazing-incidence small-angle X-ray scattering measurements during slot-die coating. The soft crystallization process shows six distinct stages: dilute dispersion, concentrated dispersion, wet film, structuring wet film, gel film, and glassy film. The close packing develops first in the in-plane direction with rapid domain growth and then advances in the out-of-plane direction. Precursors in the interstitial voids play a key role by mitigating packing frustration and favoring face-centered cubic (FCC) ordering. The structure finally stabilizes into a well-ordered FCC structure with large domain sizes. The derived mesoporous SnO2 features semiconducting properties and enhanced pore connectivity, thus showing superior gas sensing performance toward ethanol.
1335.
K Merkel, M F X Dorfner, M Engel, G Kresse, F Ortmann
In: Journal of Physics-Materials, Bd. 8, Nr. 4, 2025.
@article{nokey,
title = {Evaluating first-principles electron-phonon couplings: consistency across methods and implementations},
author = {K Merkel and M F X Dorfner and M Engel and G Kresse and F Ortmann},
url = {\<Go to ISI\>://WOS:001599552200001},
doi = {10.1088/2515-7639/ae0ef1},
year = {2025},
date = {2025-10-01},
journal = {Journal of Physics-Materials},
volume = {8},
number = {4},
abstract = {Electron-phonon coupling (EPC) is fundamental for understanding the behavior of molecules and crystals, influencing phenomena such as charge transport, energy transfer, phase transitions, and polaron formation. Accurate computational methods to calculate EPCs from first principles are essential, but their complexity has resulted in a variety of computational strategies, raising concerns about their mutual consistency. In this study, we provide a systematic benchmark of methods for EPC calculation by comparing two fundamentally different ab initio methodologies. We investigate Gaussian-type orbital methods based on the CP2K code and plane-wave-based projector-augmented-wave methods combined with maximally localized Wannier functions, as implemented in VASP and wannier90. In addition, we further distinguish between the derivative-of-Hamiltonian ( dH) and derivative-of-states ( d psi) approaches for obtaining EPC parameters. The comparison is conducted on a representative set of organic molecules, including pyrazine, pyridine, bithiophene, and quarterthiophene, varying significantly in size and flexibility. We find excellent agreement across implementations and basis sets when employing the same computational approach ( dH or d psi), demonstrating robust consistency between the numerical schemes. However, noticeable deviations occur when comparing the dH and d psi approaches within each code and for specific cases discussed in detail. Our findings emphasize the reliability of EPC computations using the dH method and caution against potential pitfalls associated with the d psi approach, providing guidance for future EPC calculations and model parameterizations.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Electron-phonon coupling (EPC) is fundamental for understanding the behavior of molecules and crystals, influencing phenomena such as charge transport, energy transfer, phase transitions, and polaron formation. Accurate computational methods to calculate EPCs from first principles are essential, but their complexity has resulted in a variety of computational strategies, raising concerns about their mutual consistency. In this study, we provide a systematic benchmark of methods for EPC calculation by comparing two fundamentally different ab initio methodologies. We investigate Gaussian-type orbital methods based on the CP2K code and plane-wave-based projector-augmented-wave methods combined with maximally localized Wannier functions, as implemented in VASP and wannier90. In addition, we further distinguish between the derivative-of-Hamiltonian ( dH) and derivative-of-states ( d psi) approaches for obtaining EPC parameters. The comparison is conducted on a representative set of organic molecules, including pyrazine, pyridine, bithiophene, and quarterthiophene, varying significantly in size and flexibility. We find excellent agreement across implementations and basis sets when employing the same computational approach ( dH or d psi), demonstrating robust consistency between the numerical schemes. However, noticeable deviations occur when comparing the dH and d psi approaches within each code and for specific cases discussed in detail. Our findings emphasize the reliability of EPC computations using the dH method and caution against potential pitfalls associated with the d psi approach, providing guidance for future EPC calculations and model parameterizations.
1334.
J S Zhang, L Xie, Z R Li, Y C Zhang, M B Faheem, G J Pan, A Buyan-Arivjikh, X Z Jiang, L X Li, M Schwartzkopf, B Sochor, S K Vayalil, Q Qiao, Z Y Ge, P Müller-Buschbaum
In: Nano Energy, Bd. 143, 2025, ISSN: 2211-2855.
@article{nokey,
title = {Real-time probing of the interplay between spinodal decomposition and crystallization during morphological evolution in printed organic solar cells},
author = {J S Zhang and L Xie and Z R Li and Y C Zhang and M B Faheem and G J Pan and A Buyan-Arivjikh and X Z Jiang and L X Li and M Schwartzkopf and B Sochor and S K Vayalil and Q Qiao and Z Y Ge and P M\"{u}ller-Buschbaum},
url = {\<Go to ISI\>://WOS:001529811300001},
doi = {10.1016/j.nanoen.2025.111301},
issn = {2211-2855},
year = {2025},
date = {2025-10-01},
journal = {Nano Energy},
volume = {143},
abstract = {The performance of organic solar cells (OSCs) strongly depends on the phase separation and crystalline properties within the active layer. However, the lack of deep understanding of morphological evolution, particularly regarding spinodal decomposition and crystallization mechanisms, presents substantial challenges in achieving precise morphological control. In this work, we systematically investigate the film formation of PBDB-TF-TTz: BTP-4F-24 blends during slot-die coating while comparing o-xylene and chlorobenzene (CB) as solvents to create distinct polymer/solvent/non-solvent systems. The complex interplay between the spinodal decomposition and crystallization processes is elucidated through complementary in situ grazing incidence small-angle Xray scattering (GISAXS) and in situ grazing incidence wide-angle X-ray scattering (GIWAXS) together with the calculation of spinodal curves. Our findings indicate that CB-processed active layers generate larger initial clusters, promoting domain coarsening while suppressing crystallization. In contrast, o-xylene-processed films exhibit optimized phase separation, larger crystallites, and face-on molecular orientations, enhancing charge transport. Additionally, polymer-dominated thermodynamic and kinetic evolution plays a critical role in shaping out the final morphology. Consequently, OSCs fabricated with o-xylene achieve higher power conversion efficiency than those processed with CB. These insights enrich the understanding of morphological evolution and provide valuable guidelines for morphology optimization.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The performance of organic solar cells (OSCs) strongly depends on the phase separation and crystalline properties within the active layer. However, the lack of deep understanding of morphological evolution, particularly regarding spinodal decomposition and crystallization mechanisms, presents substantial challenges in achieving precise morphological control. In this work, we systematically investigate the film formation of PBDB-TF-TTz: BTP-4F-24 blends during slot-die coating while comparing o-xylene and chlorobenzene (CB) as solvents to create distinct polymer/solvent/non-solvent systems. The complex interplay between the spinodal decomposition and crystallization processes is elucidated through complementary in situ grazing incidence small-angle Xray scattering (GISAXS) and in situ grazing incidence wide-angle X-ray scattering (GIWAXS) together with the calculation of spinodal curves. Our findings indicate that CB-processed active layers generate larger initial clusters, promoting domain coarsening while suppressing crystallization. In contrast, o-xylene-processed films exhibit optimized phase separation, larger crystallites, and face-on molecular orientations, enhancing charge transport. Additionally, polymer-dominated thermodynamic and kinetic evolution plays a critical role in shaping out the final morphology. Consequently, OSCs fabricated with o-xylene achieve higher power conversion efficiency than those processed with CB. These insights enrich the understanding of morphological evolution and provide valuable guidelines for morphology optimization.
1333.
A Tognazzi, P Franceschini, J Biechteler, E Baù, A C Cino, A Tittl, C De Angelis, L Sortino
In: Light-Science & Applications, Bd. 14, Nr. 1, 2025, ISSN: 2095-5545.
@article{nokey,
title = {Interface second harmonic generation enhancement in bulk WS2/MoS2 hetero-bilayer van der Waals nanoantennas},
author = {A Tognazzi and P Franceschini and J Biechteler and E Ba\`{u} and A C Cino and A Tittl and C De Angelis and L Sortino},
url = {\<Go to ISI\>://WOS:001582379800002},
doi = {10.1038/s41377-025-01983-y},
issn = {2095-5545},
year = {2025},
date = {2025-09-29},
journal = {Light-Science \& Applications},
volume = {14},
number = {1},
abstract = {Layered van der Waals (vdW) materials have emerged as a promising platform for nanophotonics due to large refractive indexes and giant optical anisotropy. Unlike conventional dielectrics and semiconductors, the absence of covalent bonds between layers allows for novel degrees of freedom in designing optically resonant nanophotonic structures down to the atomic scale: from the precise stacking of vertical heterostructures to controlling the twist angle between crystallographic axes. Specifically, although monolayers of transition metal dichalcogenides exhibit giant second-order nonlinear responses, their bulk counterparts with 2H stacking possess zero second-order nonlinearity. In this work, we investigate second harmonic generation (SHG) arising from the interface of WS2/MoS2 hetero-bilayer thin films with an additional SHG enhancement in nanostructured optical antennas, mediated by both the excitonic resonances and the anapole-driven field enhancement. When both conditions are met, we observe up to 102 SHG signal enhancement, compared to unstructured bilayers, with SHG conversion efficiency reaching approximate to 10-7. Our results highlights vdW materials as a platform for designing unique multilayer optical nanostructures and metamaterial, paving the way for advanced applications in nanophotonics and nonlinear optics.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Layered van der Waals (vdW) materials have emerged as a promising platform for nanophotonics due to large refractive indexes and giant optical anisotropy. Unlike conventional dielectrics and semiconductors, the absence of covalent bonds between layers allows for novel degrees of freedom in designing optically resonant nanophotonic structures down to the atomic scale: from the precise stacking of vertical heterostructures to controlling the twist angle between crystallographic axes. Specifically, although monolayers of transition metal dichalcogenides exhibit giant second-order nonlinear responses, their bulk counterparts with 2H stacking possess zero second-order nonlinearity. In this work, we investigate second harmonic generation (SHG) arising from the interface of WS2/MoS2 hetero-bilayer thin films with an additional SHG enhancement in nanostructured optical antennas, mediated by both the excitonic resonances and the anapole-driven field enhancement. When both conditions are met, we observe up to 102 SHG signal enhancement, compared to unstructured bilayers, with SHG conversion efficiency reaching approximate to 10-7. Our results highlights vdW materials as a platform for designing unique multilayer optical nanostructures and metamaterial, paving the way for advanced applications in nanophotonics and nonlinear optics.
1332.
D A Egger, M Grumet, T Bucko
Machine learning accelerates Raman computations from molecular dynamics for materials science Artikel
In: Journal of Chemical Physics, Bd. 163, Nr. 12, 2025, ISSN: 0021-9606.
@article{nokey,
title = {Machine learning accelerates Raman computations from molecular dynamics for materials science},
author = {D A Egger and M Grumet and T Bucko},
url = {\<Go to ISI\>://WOS:001588042700001},
doi = {10.1063/5.0287358},
issn = {0021-9606},
year = {2025},
date = {2025-09-28},
journal = {Journal of Chemical Physics},
volume = {163},
number = {12},
abstract = {Raman spectroscopy is a powerful experimental technique for characterizing molecules and materials that is used in many laboratories. First-principles theoretical calculations of Raman spectra are important because they elucidate the microscopic effects underlying Raman activity in these systems. These calculations are often performed using the canonical harmonic approximation, which cannot capture certain thermal changes in the Raman response. Anharmonic vibrational effects were recently found to play crucial roles in several materials, which motivates theoretical treatments of the Raman effect beyond harmonic phonons. While Raman spectroscopy from molecular dynamics (MD-Raman) is a well-established approach that includes anharmonic vibrations and further relevant thermal effects, MD-Raman computations were long considered to be computationally too expensive for practical materials computations. In this perspective article, we highlight that recent advances in the context of machine learning have now dramatically accelerated the involved computational tasks without sacrificing accuracy or predictive power. These recent developments highlight the increasing importance of MD-Raman and related methods as versatile tools for theoretical prediction and characterization of molecules and materials. (c) 2025 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Raman spectroscopy is a powerful experimental technique for characterizing molecules and materials that is used in many laboratories. First-principles theoretical calculations of Raman spectra are important because they elucidate the microscopic effects underlying Raman activity in these systems. These calculations are often performed using the canonical harmonic approximation, which cannot capture certain thermal changes in the Raman response. Anharmonic vibrational effects were recently found to play crucial roles in several materials, which motivates theoretical treatments of the Raman effect beyond harmonic phonons. While Raman spectroscopy from molecular dynamics (MD-Raman) is a well-established approach that includes anharmonic vibrations and further relevant thermal effects, MD-Raman computations were long considered to be computationally too expensive for practical materials computations. In this perspective article, we highlight that recent advances in the context of machine learning have now dramatically accelerated the involved computational tasks without sacrificing accuracy or predictive power. These recent developments highlight the increasing importance of MD-Raman and related methods as versatile tools for theoretical prediction and characterization of molecules and materials. (c) 2025 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).
1331.
H T Yu, R Sechi, Q D Liao, M S Nissen, A Bhowmik, E L Gubanova, K T Song, H A Hansen, A S Bandarenka
Adsorption Dynamics and Electric Double Layer Properties at Pt(100) Electrodes Artikel
In: Advanced Materials Interfaces, 2025, ISSN: 2196-7350.
@article{nokey,
title = {Adsorption Dynamics and Electric Double Layer Properties at Pt(100) Electrodes},
author = {H T Yu and R Sechi and Q D Liao and M S Nissen and A Bhowmik and E L Gubanova and K T Song and H A Hansen and A S Bandarenka},
url = {\<Go to ISI\>://WOS:001581808300001},
doi = {10.1002/admi.202500680},
issn = {2196-7350},
year = {2025},
date = {2025-09-26},
journal = {Advanced Materials Interfaces},
abstract = {The electrode-electrolyte interface governs many functional properties and processes, such as reaction rates, efficiency, and selectivity in electrochemical systems, with its structure and physicochemical phenomena being crucial for optimizing energy conversion and storage technologies. Platinum (Pt) is a state-of-the-art catalyst for numerous electrocatalytic reactions. While Pt(111) is extensively studied, atomic-level insights into interfacial properties of another basic surface, Pt(100), remain unresolved. Here, experimental techniques and first-principles calculations are utilized to investigate adsorption behavior and adsorbate coverage at varying potentials as well as interfacial entropy in acidic media. The results reveal four voltammetric peak features: below peak I, hydrogen is the predominant adsorbate; between peak II and peak III, a mixed adsorption region with 22% hydroxide and 44% hydrogen forms, while at higher potentials, hydroxide coverage increases. The double-layer structure is also explored, finding sensitivity of the double-layer capacitance to electrode surface structure. For the first time, by combining in situ laser-induced current transient and Raman spectroscopy, two potential values of maximum entropy are identified, indicating enhanced disorder and facilitated charge transfer, supported by disruption of the hydrogen-bond network due to increased dangling bonds. These insights guide the rational design of efficient electrode-electrolyte interfaces in Pt-based nanostructured materials.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The electrode-electrolyte interface governs many functional properties and processes, such as reaction rates, efficiency, and selectivity in electrochemical systems, with its structure and physicochemical phenomena being crucial for optimizing energy conversion and storage technologies. Platinum (Pt) is a state-of-the-art catalyst for numerous electrocatalytic reactions. While Pt(111) is extensively studied, atomic-level insights into interfacial properties of another basic surface, Pt(100), remain unresolved. Here, experimental techniques and first-principles calculations are utilized to investigate adsorption behavior and adsorbate coverage at varying potentials as well as interfacial entropy in acidic media. The results reveal four voltammetric peak features: below peak I, hydrogen is the predominant adsorbate; between peak II and peak III, a mixed adsorption region with 22% hydroxide and 44% hydrogen forms, while at higher potentials, hydroxide coverage increases. The double-layer structure is also explored, finding sensitivity of the double-layer capacitance to electrode surface structure. For the first time, by combining in situ laser-induced current transient and Raman spectroscopy, two potential values of maximum entropy are identified, indicating enhanced disorder and facilitated charge transfer, supported by disruption of the hydrogen-bond network due to increased dangling bonds. These insights guide the rational design of efficient electrode-electrolyte interfaces in Pt-based nanostructured materials.
1330.
S N Deger, A Mauri, Y Cui, S J Weishäupl, A D Özdemir, H Syed, A Ovsianikov, W Wenzel, A Pöthig, J Hauer, M Kozlowska, R A Fischer
In: Advanced Functional Materials, 2025, ISSN: 1616-301X.
@article{nokey,
title = {Intermolecular Interactions as Driving Force of Increasing Multiphoton Absorption in a Perylene Diimide-Based Coordination Polymer},
author = {S N Deger and A Mauri and Y Cui and S J Weish\"{a}upl and A D \"{O}zdemir and H Syed and A Ovsianikov and W Wenzel and A P\"{o}thig and J Hauer and M Kozlowska and R A Fischer},
url = {\<Go to ISI\>://WOS:001576960600001},
doi = {10.1002/adfm.202424656},
issn = {1616-301X},
year = {2025},
date = {2025-09-23},
journal = {Advanced Functional Materials},
abstract = {Coordination polymers (CPs) represent an innovative class of materials with proven potential for multiphoton absorption applications. However, understanding the structure-property relationships that govern their nonlinear optical behavior remains challenging. This study presents an in-depth investigation of the effects of intermolecular interactions on multiphoton absorption by focusing on the synthesis and characterization of 1,6,7,12-tetrachloroperylenediimide-N,N'-di-(acetic acid) (H2tpda) and its coordination with zinc to form [Zn2tpda(DMA)2(DMF)0.3] (Zntpda). How the packing of tpda linkers within the coordination framework influences their optical properties is revealed. The analysis demonstrates that Zntpda exhibits a broadened UV-vis absorption spectrum with no emission indicative of H-type aggregation with additional evidence of a photo-induced electron transfer. Z-scan measurements show enhanced two-photon absorption (2PA) cross-sections of Zntpda compared to H2tpda and even three-photon absorption (3PA). This is explained by intermolecular interactions, electronic coupling, and spatial confinement effects within the polymer. The findings underscore the critical role of chromophore orientation and packing in optimizing nonlinear optical performance, offering insights for designing advanced functional CP materials tailored for photonic applications.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Coordination polymers (CPs) represent an innovative class of materials with proven potential for multiphoton absorption applications. However, understanding the structure-property relationships that govern their nonlinear optical behavior remains challenging. This study presents an in-depth investigation of the effects of intermolecular interactions on multiphoton absorption by focusing on the synthesis and characterization of 1,6,7,12-tetrachloroperylenediimide-N,N'-di-(acetic acid) (H2tpda) and its coordination with zinc to form [Zn2tpda(DMA)2(DMF)0.3] (Zntpda). How the packing of tpda linkers within the coordination framework influences their optical properties is revealed. The analysis demonstrates that Zntpda exhibits a broadened UV-vis absorption spectrum with no emission indicative of H-type aggregation with additional evidence of a photo-induced electron transfer. Z-scan measurements show enhanced two-photon absorption (2PA) cross-sections of Zntpda compared to H2tpda and even three-photon absorption (3PA). This is explained by intermolecular interactions, electronic coupling, and spatial confinement effects within the polymer. The findings underscore the critical role of chromophore orientation and packing in optimizing nonlinear optical performance, offering insights for designing advanced functional CP materials tailored for photonic applications.
1329.
S N Deger, H P Hernandez, Y Cui, H X Hao, V Ramm, D C Mayer, K Truong, R A Fischer, J Hauer, M Kozlowska, A Pöthig
In: Advanced Functional Materials, 2025, ISSN: 1616-301X.
@article{nokey,
title = {Modulating Two-Photon Absorption in a Pyrene-Based MOF Series: An In-Depth Investigation of Structure-Property Relationships},
author = {S N Deger and H P Hernandez and Y Cui and H X Hao and V Ramm and D C Mayer and K Truong and R A Fischer and J Hauer and M Kozlowska and A P\"{o}thig},
url = {\<Go to ISI\>://WOS:001575580000001},
doi = {10.1002/adfm.202506660},
issn = {1616-301X},
year = {2025},
date = {2025-09-22},
journal = {Advanced Functional Materials},
abstract = {Metal-organic frameworks (MOFs) are emerging as promising materials for multiphoton absorption (MPA), a nonlinear optical phenomenon relevant for applications, such as bioimaging, phototherapy, and photonic devices. However, the structural features that govern their exceptional MPA activity remain poorly understood. To address this, a family of pyrene-based MOFs (NU-1000, NU-901, SrTBAPy, and BaTBAPy), that vary in topology and secondary building units (SBUs), is systematically investigated. Significant differences are observed in the two-photon absorption (2PA) cross-section sigma (2), with BaTBAPy exhibiting the highest activity (8.2 x 104 GM). Quantum mechanical calculations reveal that intermolecular chromophore interactions and SBU-induced effects contribute strongly to enhanced sigma (2) values, particularly in NU-901 and BaTBAPy. The findings demonstrate that both framework topology and metal coordination environments are critical to modulating MPA behavior. These insights into the structure-property relationships of MOFs pave the way for rational design of next-generation nonlinear optical materials.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Metal-organic frameworks (MOFs) are emerging as promising materials for multiphoton absorption (MPA), a nonlinear optical phenomenon relevant for applications, such as bioimaging, phototherapy, and photonic devices. However, the structural features that govern their exceptional MPA activity remain poorly understood. To address this, a family of pyrene-based MOFs (NU-1000, NU-901, SrTBAPy, and BaTBAPy), that vary in topology and secondary building units (SBUs), is systematically investigated. Significant differences are observed in the two-photon absorption (2PA) cross-section sigma (2), with BaTBAPy exhibiting the highest activity (8.2 x 104 GM). Quantum mechanical calculations reveal that intermolecular chromophore interactions and SBU-induced effects contribute strongly to enhanced sigma (2) values, particularly in NU-901 and BaTBAPy. The findings demonstrate that both framework topology and metal coordination environments are critical to modulating MPA behavior. These insights into the structure-property relationships of MOFs pave the way for rational design of next-generation nonlinear optical materials.
1328.
H H Heenen, K Reuter
On Boltzmann averaging in ab initio thermodynamics Artikel
In: Journal of Chemical Physics, Bd. 163, Nr. 11, 2025, ISSN: 0021-9606.
@article{nokey,
title = {On Boltzmann averaging in ab initio thermodynamics},
author = {H H Heenen and K Reuter},
url = {\<Go to ISI\>://WOS:001573825800001},
doi = {10.1063/5.0285752},
issn = {0021-9606},
year = {2025},
date = {2025-09-21},
journal = {Journal of Chemical Physics},
volume = {163},
number = {11},
abstract = {Ab initio thermodynamics is a widespread, computationally efficient approach to predict the stable configuration of a surface in contact with a surrounding (gas or liquid) environment. In a prevalent realization of this approach, this stable configuration is simply equated with the structure in a considered candidate pool that exhibits the lowest surface free energy. Here, we discuss the possibility to consider the thermal accessibility of competing, higher-energy configurations through Boltzmann averaging when extended surface configurations and their energetics are computed within periodic boundary condition supercells. We show analytically that fully converged averages can be obtained with a candidate pool derived from exhaustive sampling in a surface unit-cell exceeding the system's correlation length. In contrast, averaging over a small pool of ad hoc assembled structures is generally ill-defined. Enumerations of a lattice-gas Hamiltonian model for on-surface oxygen adsorption at Pd(100) are employed to illustrate these considerations in a practical context. (c) 2025 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Ab initio thermodynamics is a widespread, computationally efficient approach to predict the stable configuration of a surface in contact with a surrounding (gas or liquid) environment. In a prevalent realization of this approach, this stable configuration is simply equated with the structure in a considered candidate pool that exhibits the lowest surface free energy. Here, we discuss the possibility to consider the thermal accessibility of competing, higher-energy configurations through Boltzmann averaging when extended surface configurations and their energetics are computed within periodic boundary condition supercells. We show analytically that fully converged averages can be obtained with a candidate pool derived from exhaustive sampling in a surface unit-cell exceeding the system's correlation length. In contrast, averaging over a small pool of ad hoc assembled structures is generally ill-defined. Enumerations of a lattice-gas Hamiltonian model for on-surface oxygen adsorption at Pd(100) are employed to illustrate these considerations in a practical context. (c) 2025 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license.
1327.
Q Y Wang, Y S Xiao, F Li, Y Tan, Y X Liu, F Gröbmeyer, K Liu, J W Fu, H M Li, C W Kao, T S Chan, R K Miao, L Y Chai, E Cortés, M Liu
Engineering Interlayer Electric Fields to Enhance K+ Insertion for Efficient Acidic CO2 Reduction Artikel
In: Acs Catalysis, Bd. 15, Nr. 18, S. 15920-15928, 2025, ISSN: 2155-5435.
@article{nokey,
title = {Engineering Interlayer Electric Fields to Enhance K+ Insertion for Efficient Acidic CO2 Reduction},
author = {Q Y Wang and Y S Xiao and F Li and Y Tan and Y X Liu and F Gr\"{o}bmeyer and K Liu and J W Fu and H M Li and C W Kao and T S Chan and R K Miao and L Y Chai and E Cort\'{e}s and M Liu},
url = {\<Go to ISI\>://WOS:001565586300001},
doi = {10.1021/acscatal.5c03353},
issn = {2155-5435},
year = {2025},
date = {2025-09-19},
journal = {Acs Catalysis},
volume = {15},
number = {18},
pages = {15920-15928},
abstract = {In acidic CO2 electroreduction reaction (CO2RR), excessive H* adsorption from high proton concentrations suppresses *CO coverage on Cu-based catalysts, limiting multicarbon (C2+) product formation. Here, we introduce a K+ insertion strategy via an interlayer electric field (IEF) between the layers of Cu nanosheets (K+-Cu NS) to strengthen *CO adsorption and boost C2+ selectivity. Finite element method (FEM) simulations verified the role of the IEF in enriching K+ ions, meanwhile density functional theory (DFT) calculations demonstrated these enriched K+ ions facilitate stronger *CO adsorption. Ar+ ion-etching-assisted X-ray photoelectron spectroscopy (XPS) and operando Raman spectroscopy confirmed the structured K+ stuffing. Operando attenuated total reflection infrared spectroscopy (ATR-IR) demonstrated the enhanced *CO adsorption on K+-Cu NS. As a result, the K+-Cu NS catalyst achieved an ultrahigh cathodic energy efficiency of 42.5% and a remarkable Faradaic efficiency of 80.3% for C2+ products in a flow cell. This work highlights a novel cation regulation strategy for advancing the acidic CO2RR efficiency.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
In acidic CO2 electroreduction reaction (CO2RR), excessive H* adsorption from high proton concentrations suppresses *CO coverage on Cu-based catalysts, limiting multicarbon (C2+) product formation. Here, we introduce a K+ insertion strategy via an interlayer electric field (IEF) between the layers of Cu nanosheets (K+-Cu NS) to strengthen *CO adsorption and boost C2+ selectivity. Finite element method (FEM) simulations verified the role of the IEF in enriching K+ ions, meanwhile density functional theory (DFT) calculations demonstrated these enriched K+ ions facilitate stronger *CO adsorption. Ar+ ion-etching-assisted X-ray photoelectron spectroscopy (XPS) and operando Raman spectroscopy confirmed the structured K+ stuffing. Operando attenuated total reflection infrared spectroscopy (ATR-IR) demonstrated the enhanced *CO adsorption on K+-Cu NS. As a result, the K+-Cu NS catalyst achieved an ultrahigh cathodic energy efficiency of 42.5% and a remarkable Faradaic efficiency of 80.3% for C2+ products in a flow cell. This work highlights a novel cation regulation strategy for advancing the acidic CO2RR efficiency.
1326.
A Carbone, D De Mongex, A V Krasheninnikov, M Wubs, A Huck, T W Hansen, A W Holleitner, N Stenger, C Kastl
In: Applied Physics Reviews, Bd. 12, Nr. 3, 2025, ISSN: 1931-9401.
@article{nokey,
title = {Creation and microscopic origins of single-photon emitters in transition-metal dichalcogenides and hexagonal boron nitride},
author = {A Carbone and D De Mongex and A V Krasheninnikov and M Wubs and A Huck and T W Hansen and A W Holleitner and N Stenger and C Kastl},
url = {\<Go to ISI\>://WOS:001577858500001},
doi = {10.1063/5.0278132},
issn = {1931-9401},
year = {2025},
date = {2025-09-19},
journal = {Applied Physics Reviews},
volume = {12},
number = {3},
abstract = {We highlight recent advances in the controlled creation of single-photon emitters in van der Waals materials and in the understanding of their atomistic origin. We focus on quantum emitters created in monolayer transition-metal dichalcogenide semiconductors, which provide spectrally sharp single-photon emission at cryogenic temperatures, and the ones in insulating hBN, which provide bright and stable single-photon emission up to room temperature. After introducing the different classes of quantum emitters in terms of band-structure properties, we review the defect creation methods based on electron and ion irradiation as well as local strain engineering and plasma treatments. A main focus of the review is put on discussing the microscopic origin of the quantum emitters as revealed by various experimental platforms, including optical and scanning probe methods.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
We highlight recent advances in the controlled creation of single-photon emitters in van der Waals materials and in the understanding of their atomistic origin. We focus on quantum emitters created in monolayer transition-metal dichalcogenide semiconductors, which provide spectrally sharp single-photon emission at cryogenic temperatures, and the ones in insulating hBN, which provide bright and stable single-photon emission up to room temperature. After introducing the different classes of quantum emitters in terms of band-structure properties, we review the defect creation methods based on electron and ion irradiation as well as local strain engineering and plasma treatments. A main focus of the review is put on discussing the microscopic origin of the quantum emitters as revealed by various experimental platforms, including optical and scanning probe methods.
1325.
A Rodríguez-Camargo, E Yildiz, D Juela, F R Fischer, D Graf, B B Rath, C Ochsenfeld, M Bauer, M Sitti, L Yao, B V Lotsch
In: Journal of the American Chemical Society, Bd. 147, Nr. 37, S. 33472-33481, 2025, ISSN: 0002-7863.
@article{nokey,
title = {Mixed-Length Multivariate Covalent Organic Framework for Combined Near-Infrared Photodynamic Therapy and Drug Delivery},
author = {A Rodr\'{i}guez-Camargo and E Yildiz and D Juela and F R Fischer and D Graf and B B Rath and C Ochsenfeld and M Bauer and M Sitti and L Yao and B V Lotsch},
url = {\<Go to ISI\>://WOS:001566346900001},
doi = {10.1021/jacs.5c07787},
issn = {0002-7863},
year = {2025},
date = {2025-09-17},
journal = {Journal of the American Chemical Society},
volume = {147},
number = {37},
pages = {33472-33481},
abstract = {Covalent organic frameworks (COFs) have been emerging as versatile reticular materials due to their tunable structures and functionalities, enabled by precise molecular engineering at the atomic level. While the integration of multiple components into COFs has substantially expanded their structural complexity, the strategic engineering of diverse functionalities within a single framework via the random distribution of linkers with varying lengths remains largely unexplored. Here, we report a series of highly crystalline mixed-length multivariate COFs synthesized using azobenzene and bipyridine as linkers, where tuning the ratio of linkers and incorporating palladium effectively modulates the balance between near-infrared (NIR) light absorption and catalytic sites for NIR-generation of hydrogen peroxide (H2O2). Capitalizing on the deep tissue penetration of NIR light and the generated H2O2 as reactive oxygen species, as a proof of concept, the optimal mixed-length multivariate COF reduces breast cancer cell viability by almost 90% after 1 h of irradiation in a combined in vitro photodynamic therapy and drug delivery.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Covalent organic frameworks (COFs) have been emerging as versatile reticular materials due to their tunable structures and functionalities, enabled by precise molecular engineering at the atomic level. While the integration of multiple components into COFs has substantially expanded their structural complexity, the strategic engineering of diverse functionalities within a single framework via the random distribution of linkers with varying lengths remains largely unexplored. Here, we report a series of highly crystalline mixed-length multivariate COFs synthesized using azobenzene and bipyridine as linkers, where tuning the ratio of linkers and incorporating palladium effectively modulates the balance between near-infrared (NIR) light absorption and catalytic sites for NIR-generation of hydrogen peroxide (H2O2). Capitalizing on the deep tissue penetration of NIR light and the generated H2O2 as reactive oxygen species, as a proof of concept, the optimal mixed-length multivariate COF reduces breast cancer cell viability by almost 90% after 1 h of irradiation in a combined in vitro photodynamic therapy and drug delivery.
1324.
J Figueiredo, M Richter, M Troue, J Kiemle, H Lambers, T Stiehm, T Taniguchi, K Watanabe, U Wurstbauer, A Knorr, A W Holleitner
Laterally extended states of interlayer excitons in reconstructed MoSe2/WSe2 heterostructures Artikel
In: Npj Quantum Materials, Bd. 10, Nr. 1, 2025.
@article{nokey,
title = {Laterally extended states of interlayer excitons in reconstructed MoSe2/WSe2 heterostructures},
author = {J Figueiredo and M Richter and M Troue and J Kiemle and H Lambers and T Stiehm and T Taniguchi and K Watanabe and U Wurstbauer and A Knorr and A W Holleitner},
url = {\<Go to ISI\>://WOS:001572052800001},
doi = {10.1038/s41535-025-00820-0},
year = {2025},
date = {2025-09-16},
journal = {Npj Quantum Materials},
volume = {10},
number = {1},
abstract = {Heterostructures made from 2D transition-metal dichalcogenides are known as ideal platforms to explore excitonic phenomena ranging from correlated moir \& eacute; excitons to degenerate interlayer exciton ensembles. So far, it is assumed that the atomic reconstruction appearing in some of the heterostructures gives rise to a dominating localization of the exciton states. We demonstrate that the center-of-mass wavefunction of the excitonic states in reconstructed MoSe2/WSe2 heterostructures can extend well beyond the moir \& eacute; periodicity of the investigated heterostructures. The results are based on real-space calculations yielding a lateral potential map for interlayer excitons within the strain-relaxed heterostructures with weak random disorder, as expected for realistic samples, and the corresponding real-space center-of-mass excitonic wavefunctions. We combine the theoretical results with cryogenic photoluminescence experiments, which support the computed level structure and relaxation characteristics of the interlayer excitons.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Heterostructures made from 2D transition-metal dichalcogenides are known as ideal platforms to explore excitonic phenomena ranging from correlated moir & eacute; excitons to degenerate interlayer exciton ensembles. So far, it is assumed that the atomic reconstruction appearing in some of the heterostructures gives rise to a dominating localization of the exciton states. We demonstrate that the center-of-mass wavefunction of the excitonic states in reconstructed MoSe2/WSe2 heterostructures can extend well beyond the moir & eacute; periodicity of the investigated heterostructures. The results are based on real-space calculations yielding a lateral potential map for interlayer excitons within the strain-relaxed heterostructures with weak random disorder, as expected for realistic samples, and the corresponding real-space center-of-mass excitonic wavefunctions. We combine the theoretical results with cryogenic photoluminescence experiments, which support the computed level structure and relaxation characteristics of the interlayer excitons.
1323.
X F Zhou, R Herboth, J Z Liu, B Shen, J W Zhai, E Cortés, J Y Yuan, A P Lyubartsev, N Hedin
Direct Synthesis of Hydrogen Peroxide from Water and Alcohol Using Ultrasound Artikel
In: Acs Sustainable Chemistry & Engineering, Bd. 13, Nr. 36, S. 14677-14682, 2025, ISSN: 2168-0485.
@article{nokey,
title = {Direct Synthesis of Hydrogen Peroxide from Water and Alcohol Using Ultrasound},
author = {X F Zhou and R Herboth and J Z Liu and B Shen and J W Zhai and E Cort\'{e}s and J Y Yuan and A P Lyubartsev and N Hedin},
url = {\<Go to ISI\>://WOS:001565430700001},
doi = {10.1021/acssuschemeng.5c04558},
issn = {2168-0485},
year = {2025},
date = {2025-09-15},
journal = {Acs Sustainable Chemistry \& Engineering},
volume = {13},
number = {36},
pages = {14677-14682},
abstract = {Generating hydrogen peroxide (H2O2) within aqueous or eco-friendly solvent systems presents significant challenges due to the complex reaction dynamics and the need for highly selective and stable catalysts. Herein, we report the production of H2O2 with an exceeding rate of one millimole per liter per hour in the absence of catalysts, achieved by agitating aerated ethanol-aqueous solutions with ultrasound. This result is attributed to the water charge transfer, which induces charged water molecules to react with dissolved oxygen and ethanol, respectively. In addition, the diffusion of the superoxide radical is faster in ethanol aqueous solutions than in pure water or in ethanol alone, contributing to the high rate of H2O2 generation. Our technology provides new insights into sonochemistry and establishes a green synthetic system for H2O2 production.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Generating hydrogen peroxide (H2O2) within aqueous or eco-friendly solvent systems presents significant challenges due to the complex reaction dynamics and the need for highly selective and stable catalysts. Herein, we report the production of H2O2 with an exceeding rate of one millimole per liter per hour in the absence of catalysts, achieved by agitating aerated ethanol-aqueous solutions with ultrasound. This result is attributed to the water charge transfer, which induces charged water molecules to react with dissolved oxygen and ethanol, respectively. In addition, the diffusion of the superoxide radical is faster in ethanol aqueous solutions than in pure water or in ethanol alone, contributing to the high rate of H2O2 generation. Our technology provides new insights into sonochemistry and establishes a green synthetic system for H2O2 production.
1322.
E Baù, A Aigner, J Biechteler, C Heimig, T Weber, T Gölz, S A Maier, A Tittl
In: Advanced Materials, 2025, ISSN: 0935-9648.
@article{nokey,
title = {Spatially Encoded Polaritonic Ultra-Strong Coupling in Gradient Metasurfaces with Epsilon-Near-Zero Modes},
author = {E Ba\`{u} and A Aigner and J Biechteler and C Heimig and T Weber and T G\"{o}lz and S A Maier and A Tittl},
url = {\<Go to ISI\>://WOS:001568984600001},
doi = {10.1002/adma.202510402},
issn = {0935-9648},
year = {2025},
date = {2025-09-12},
journal = {Advanced Materials},
abstract = {A platform is introduced to achieve ultra-strong coupling (USC) between light and matter using widely available materials. USC is a light-matter interaction regime characterized by coupling strengths exceeding 10% of the ground state energy. It gives rise to novel physical phenomena, such as efficient single-photon coupling and quantum gates, with applications in quantum sensing, nonlinear optics, and low-threshold lasing. Although early demonstrations in plasmonic systems have been realized, achieving USC in dielectric platforms, which offer lower losses and high Q-factors, remains challenging due to typically low mode overlap between the photonic field and the material resonance. Here, dielectric dual gradient metasurfaces supporting quasi-bound-states-in-the-continuum are leveraged to spatially encode both the spectral and coupling parameter space and demonstrate USC to an epsilon-near-zero (ENZ) mode in an ultra-thin SiO2 layer. The strong out-of-plane electric fields in tapered bar structure overlap exceptionally well with those of the ENZ mode, resulting in a normalized coupling strength of eta = 0.10 and a mode splitting equivalent to 20% of the ENZ mode energy; a four-to-five-fold increase compared to previous approaches. The strong field confinement of the approach opens new possibilities for compact and scalable polaritonic devices, such as tunable frequency converters and low-energy optical modulators.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
A platform is introduced to achieve ultra-strong coupling (USC) between light and matter using widely available materials. USC is a light-matter interaction regime characterized by coupling strengths exceeding 10% of the ground state energy. It gives rise to novel physical phenomena, such as efficient single-photon coupling and quantum gates, with applications in quantum sensing, nonlinear optics, and low-threshold lasing. Although early demonstrations in plasmonic systems have been realized, achieving USC in dielectric platforms, which offer lower losses and high Q-factors, remains challenging due to typically low mode overlap between the photonic field and the material resonance. Here, dielectric dual gradient metasurfaces supporting quasi-bound-states-in-the-continuum are leveraged to spatially encode both the spectral and coupling parameter space and demonstrate USC to an epsilon-near-zero (ENZ) mode in an ultra-thin SiO2 layer. The strong out-of-plane electric fields in tapered bar structure overlap exceptionally well with those of the ENZ mode, resulting in a normalized coupling strength of eta = 0.10 and a mode splitting equivalent to 20% of the ENZ mode energy; a four-to-five-fold increase compared to previous approaches. The strong field confinement of the approach opens new possibilities for compact and scalable polaritonic devices, such as tunable frequency converters and low-energy optical modulators.
1321.
L Zhu, K Liu, H J W Li, Z W Mei, Y C Kang, Q Chen, X J Wang, H Zhang, X Zi, Q Y Wang, J W Fu, E Pensa, A Stefancu, M Liu, E Cortés
Plasmon-Enhanced C2H4 Generation in the CO2 Electroreduction Reaction on a CuPd Tandem Catalyst Artikel
In: Journal of the American Chemical Society, Bd. 147, Nr. 36, S. 33003-33009, 2025, ISSN: 0002-7863.
@article{nokey,
title = {Plasmon-Enhanced C2H4 Generation in the CO2 Electroreduction Reaction on a CuPd Tandem Catalyst},
author = {L Zhu and K Liu and H J W Li and Z W Mei and Y C Kang and Q Chen and X J Wang and H Zhang and X Zi and Q Y Wang and J W Fu and E Pensa and A Stefancu and M Liu and E Cort\'{e}s},
url = {\<Go to ISI\>://WOS:001559019100001},
doi = {10.1021/jacs.5c10517},
issn = {0002-7863},
year = {2025},
date = {2025-09-10},
journal = {Journal of the American Chemical Society},
volume = {147},
number = {36},
pages = {33003-33009},
abstract = {Electrocatalysis enables the conversion of CO2 into value-added fuels and chemicals, offering a sustainable solution for greenhouse gas mitigation. However, achieving high selectivity for C2 products like ethylene (C2H4) remains challenging due to competing C1 pathways and complex multielectron processes. Here, we demonstrate that plasmon resonances can selectively enhance the electroreduction of CO2 to C2H4 by 27.0% on a CuPd catalyst under LED illumination (625 nm) at -1.3 VRHE. Photocurrent response, in situ FTIR spectroscopy, and COMSOL simulations reveal that plasmon-derived hot electrons and heating greatly facilitate *CO formation at the CuPd interface, which diffuses to the Cu surface for subsequent C-C coupling. DFT calculations show that the increased *CO coverage on the Cu sites reduces the energy barrier for C-C coupling, ultimately enhancing C2H4 generation. This work offers valuable mechanistic insights into plasmon-mediated electrocatalysis, guiding the development of more efficient plasmonic tandem electrocatalysts for future carbon recycling technologies.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Electrocatalysis enables the conversion of CO2 into value-added fuels and chemicals, offering a sustainable solution for greenhouse gas mitigation. However, achieving high selectivity for C2 products like ethylene (C2H4) remains challenging due to competing C1 pathways and complex multielectron processes. Here, we demonstrate that plasmon resonances can selectively enhance the electroreduction of CO2 to C2H4 by 27.0% on a CuPd catalyst under LED illumination (625 nm) at -1.3 VRHE. Photocurrent response, in situ FTIR spectroscopy, and COMSOL simulations reveal that plasmon-derived hot electrons and heating greatly facilitate *CO formation at the CuPd interface, which diffuses to the Cu surface for subsequent C-C coupling. DFT calculations show that the increased *CO coverage on the Cu sites reduces the energy barrier for C-C coupling, ultimately enhancing C2H4 generation. This work offers valuable mechanistic insights into plasmon-mediated electrocatalysis, guiding the development of more efficient plasmonic tandem electrocatalysts for future carbon recycling technologies.
1320.
N L T Pham, S M Qian, T Götsch, C Grön, J J Velasco-Vélez, B M Stühmeier, A Knop-Gericke, H A Gasteiger, M Piana
In: Acs Applied Materials & Interfaces, Bd. 17, Nr. 36, S. 50626-50638, 2025, ISSN: 1944-8244.
@article{nokey,
title = {Elucidating the Hydrogen Selectivity of Pt/TiO x /C as a Fuel-Cell Catalyst by Operando Near-Ambient-Pressure XPS},
author = {N L T Pham and S M Qian and T G\"{o}tsch and C Gr\"{o}n and J J Velasco-V\'{e}lez and B M St\"{u}hmeier and A Knop-Gericke and H A Gasteiger and M Piana},
url = {\<Go to ISI\>://WOS:001565430000001},
doi = {10.1021/acsami.5c09047},
issn = {1944-8244},
year = {2025},
date = {2025-09-10},
journal = {Acs Applied Materials \& Interfaces},
volume = {17},
number = {36},
pages = {50626-50638},
abstract = {The long-term stability of proton exchange membrane fuel cells (PEMFCs) faces significant challenges, particularly during start-up and shut-down events, which lead to degradation of the cathode catalyst through the oxidation of its carbon support. To improve catalyst durability, an anode catalyst with a high selectivity toward the hydrogen oxidation/evolution reaction rather than the oxygen reduction reaction is necessary. Pt/TiOx/C (x \< 2) catalysts have been reported to provide excellent hydrogen selectivity due to its strong metal-support interaction (SMSI) between Pt particles and TiOx support. To further elucidate the SMSI-induced effect of the catalyst, this study employs near-ambient-pressure X-ray photoelectron spectroscopy (NAP-XPS) at BESSY II with an upgraded operando cell, optimized for the use of membrane electrode assemblies (MEAs) for the first time. The electrochemical behavior of the operando cell is fully consistent with PEMFC measurements for both the standard Pt/C and investigated Pt/TiOx/C catalysts. With NAP-XPS, the SMSI-induced effect is observed through a significant suppression of Pt oxidation at high potentials for Pt/TiOx/C. A precise quantification of the oxidation charge from both electrochemical and NAP-XPS data evidently shows partial Pt oxidation for Pt/TiOx/C, clearly originating from Pt deposited on carbon instead of TiOx, as demonstrated by transmission electron microscopy. Nevertheless, the results reveal that barely any oxidation is expected for SMSI-based catalysts such as pure Pt/TiOx/C. Cracks in the bilayer graphene used as an X-ray transparent window in the operando setup likely explain the lower absolute values in Pt oxidation obtained from NAP-XPS compared with the values from electrochemistry, still allowing valuable insights into the catalyst behavior.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The long-term stability of proton exchange membrane fuel cells (PEMFCs) faces significant challenges, particularly during start-up and shut-down events, which lead to degradation of the cathode catalyst through the oxidation of its carbon support. To improve catalyst durability, an anode catalyst with a high selectivity toward the hydrogen oxidation/evolution reaction rather than the oxygen reduction reaction is necessary. Pt/TiOx/C (x < 2) catalysts have been reported to provide excellent hydrogen selectivity due to its strong metal-support interaction (SMSI) between Pt particles and TiOx support. To further elucidate the SMSI-induced effect of the catalyst, this study employs near-ambient-pressure X-ray photoelectron spectroscopy (NAP-XPS) at BESSY II with an upgraded operando cell, optimized for the use of membrane electrode assemblies (MEAs) for the first time. The electrochemical behavior of the operando cell is fully consistent with PEMFC measurements for both the standard Pt/C and investigated Pt/TiOx/C catalysts. With NAP-XPS, the SMSI-induced effect is observed through a significant suppression of Pt oxidation at high potentials for Pt/TiOx/C. A precise quantification of the oxidation charge from both electrochemical and NAP-XPS data evidently shows partial Pt oxidation for Pt/TiOx/C, clearly originating from Pt deposited on carbon instead of TiOx, as demonstrated by transmission electron microscopy. Nevertheless, the results reveal that barely any oxidation is expected for SMSI-based catalysts such as pure Pt/TiOx/C. Cracks in the bilayer graphene used as an X-ray transparent window in the operando setup likely explain the lower absolute values in Pt oxidation obtained from NAP-XPS compared with the values from electrochemistry, still allowing valuable insights into the catalyst behavior.
1319.
X Z Jiang, J Zeng, K Sun, Z R Li, G J Pan, R J Guo, M Schwartzkopf, S V Roth, B M Xu, P Müller-Buschbaum
Homogeneous FACsPbI3 Films via Sequential Deposition for Efficient and Stable Perovskite Solar Cells Artikel
In: Advanced Science, 2025.
@article{nokey,
title = {Homogeneous FACsPbI3 Films via Sequential Deposition for Efficient and Stable Perovskite Solar Cells},
author = {X Z Jiang and J Zeng and K Sun and Z R Li and G J Pan and R J Guo and M Schwartzkopf and S V Roth and B M Xu and P M\"{u}ller-Buschbaum},
url = {\<Go to ISI\>://WOS:001562671200001},
doi = {10.1002/advs.202506234},
year = {2025},
date = {2025-09-03},
journal = {Advanced Science},
abstract = {Despite significant advancements in the power conversion efficiency (PCE) of FAPbI3-based perovskite solar cells (PSCs), their commercialization remains hindered by stability issues. These challenges arise primarily from the phase transition of the alpha-phase to the delta-phase under operation. Alloying FAPbI3 with Cs to form FA-Cs perovskite (FACsPbI3) emerged as a promising approach to enhance phase and thermal stability. In this study, it is demonstrated that adding a Cs source to the PbI2 solution promotes the formation of a structurally stable alpha-phase in the PbI2 film. This stabilization reduces cation diffusion but leads to Cs accumulation at the surface of the perovskite layer. To address this issue, a delta-phase perovskite in the PbI2 film by predepositing the Cs source before PbI2 deposition is constructed. This approach facilitates the uniform vertical distribution of FA and Cs cations, resulting in a homogeneous perovskite (h-perovskite) device. The h-perovskite device achieves a higher PCE of 24.59%, compared to 22.96% for the inhomogeneous perovskite (i-perovskite) device. Operando GIWAXS measurements reveal that the h-perovskite exhibits a slower degradation rate than the i-perovskite during device operation. This difference is attributed to the formation of the delta-phase and a stronger crystal lattice contraction observed in the i-perovskite during the operando measurements.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Despite significant advancements in the power conversion efficiency (PCE) of FAPbI3-based perovskite solar cells (PSCs), their commercialization remains hindered by stability issues. These challenges arise primarily from the phase transition of the alpha-phase to the delta-phase under operation. Alloying FAPbI3 with Cs to form FA-Cs perovskite (FACsPbI3) emerged as a promising approach to enhance phase and thermal stability. In this study, it is demonstrated that adding a Cs source to the PbI2 solution promotes the formation of a structurally stable alpha-phase in the PbI2 film. This stabilization reduces cation diffusion but leads to Cs accumulation at the surface of the perovskite layer. To address this issue, a delta-phase perovskite in the PbI2 film by predepositing the Cs source before PbI2 deposition is constructed. This approach facilitates the uniform vertical distribution of FA and Cs cations, resulting in a homogeneous perovskite (h-perovskite) device. The h-perovskite device achieves a higher PCE of 24.59%, compared to 22.96% for the inhomogeneous perovskite (i-perovskite) device. Operando GIWAXS measurements reveal that the h-perovskite exhibits a slower degradation rate than the i-perovskite during device operation. This difference is attributed to the formation of the delta-phase and a stronger crystal lattice contraction observed in the i-perovskite during the operando measurements.
1318.
F Vonhoff, M J Schilcher, D R Reichman, D A Egger
Analysis of real-space transport channels for electrons and holes in halide perovskites Artikel
In: Physical Review Materials, Bd. 9, Nr. 9, 2025, ISSN: 2475-9953.
@article{nokey,
title = {Analysis of real-space transport channels for electrons and holes in halide perovskites},
author = {F Vonhoff and M J Schilcher and D R Reichman and D A Egger},
url = {\<Go to ISI\>://WOS:001564200400002},
doi = {10.1103/c4v6-kf43},
issn = {2475-9953},
year = {2025},
date = {2025-09-02},
journal = {Physical Review Materials},
volume = {9},
number = {9},
abstract = {Predicting and explaining charge carrier transport in halide perovskites is a formidable challenge because of the unusual vibrational and electron-phonon coupling properties of these materials. This study explores charge carrier transport in two prototypical halide perovskite materials, methylammonium lead tribromide (MAPbBr3) and methylammonium lead triiodide (MAPbI3), using a dynamic disorder model. Focusing on the role of realspace transport channels, we analyze temporal orbital occupations to assess the impact of material-specific onsite energy levels and spin-orbit coupling (SOC) strengths. Our findings reveal that both on-site energies and SOC magnitude significantly influence the orbital occupation dynamics, thereby affecting charge dispersal and carrier mobility. In particular, energy gaps across on-site levels and the halide SOC strength govern the filling of transport channels over time. This leads us to identify the pp pi channel as a critical bottleneck for charge transport and to provide insights into the differences between electron and hole transport across the two materials.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Predicting and explaining charge carrier transport in halide perovskites is a formidable challenge because of the unusual vibrational and electron-phonon coupling properties of these materials. This study explores charge carrier transport in two prototypical halide perovskite materials, methylammonium lead tribromide (MAPbBr3) and methylammonium lead triiodide (MAPbI3), using a dynamic disorder model. Focusing on the role of realspace transport channels, we analyze temporal orbital occupations to assess the impact of material-specific onsite energy levels and spin-orbit coupling (SOC) strengths. Our findings reveal that both on-site energies and SOC magnitude significantly influence the orbital occupation dynamics, thereby affecting charge dispersal and carrier mobility. In particular, energy gaps across on-site levels and the halide SOC strength govern the filling of transport channels over time. This leads us to identify the pp pi channel as a critical bottleneck for charge transport and to provide insights into the differences between electron and hole transport across the two materials.
1317.
P Metuh, A Paralikis, P Wyborski, S Jamo, A Palermo, L Zugliani, M Barbone, K Müller, N Gregersen, S Vaitiekénas, J Finley, B Munkhbat
Toward Single-Photon Detection with Superconducting Niobium Diselenide Nanowires Artikel
In: Acs Photonics, 2025, ISSN: 2330-4022.
@article{nokey,
title = {Toward Single-Photon Detection with Superconducting Niobium Diselenide Nanowires},
author = {P Metuh and A Paralikis and P Wyborski and S Jamo and A Palermo and L Zugliani and M Barbone and K M\"{u}ller and N Gregersen and S Vaitiek\'{e}nas and J Finley and B Munkhbat},
url = {\<Go to ISI\>://WOS:001565582300001},
doi = {10.1021/acsphotonics.5c01195},
issn = {2330-4022},
year = {2025},
date = {2025-09-02},
journal = {Acs Photonics},
abstract = {We present superconducting nanowire photodetectors based on hBN-encapsulated, few-layer NbSe2, showing signatures of single-photon sensitivity. The top-down fabrication process preserves the superconducting properties of NbSe2, as confirmed by low-temperature transport measurements showing comparable results to unpatterned sheets, and it maintains a contact and wiring resistance down to similar to 30 Omega at T = 4 K. Meandered NbSe2 nanowires exhibit high responsivity (up to 4.9 x 10(4) V/W) over a spectral range of 650-1550 nm in a closed-cycle cryostat at 4 K, outperforming samples with different geometries in this work. The meander achieves a recovery time of (135 +/- 36) ns, a system timing jitter of (1103 +/- 7) ps, and a detection efficiency of similar to 0.01% at 0.95I(c). A linear increase of the count rate with the number of photons between the noise level and the latching threshold offers a signature of single-photon sensitivity at 1100 nm.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
We present superconducting nanowire photodetectors based on hBN-encapsulated, few-layer NbSe2, showing signatures of single-photon sensitivity. The top-down fabrication process preserves the superconducting properties of NbSe2, as confirmed by low-temperature transport measurements showing comparable results to unpatterned sheets, and it maintains a contact and wiring resistance down to similar to 30 Omega at T = 4 K. Meandered NbSe2 nanowires exhibit high responsivity (up to 4.9 x 10(4) V/W) over a spectral range of 650-1550 nm in a closed-cycle cryostat at 4 K, outperforming samples with different geometries in this work. The meander achieves a recovery time of (135 +/- 36) ns, a system timing jitter of (1103 +/- 7) ps, and a detection efficiency of similar to 0.01% at 0.95I(c). A linear increase of the count rate with the number of photons between the noise level and the latching threshold offers a signature of single-photon sensitivity at 1100 nm.
1316.
M P Le Dû, D P Kosbahn, T Baier, J Reitenbach, Q Zhong, A Vagias, R Cubitt, N Chaulagain, K Shankar, H Übele, K Krischer, P Müller-Buschbaum
In: Chemsuschem, 2025, ISSN: 1864-5631.
@article{nokey,
title = {Platinum-Doped Carbon Nitride-Loaded Poly(N-Isopropylacrylamide) Hydrogel Thin Films for Green Hydrogen Production Systems: Morphological Study for Higher Efficiency},
author = {M P Le D\^{u} and D P Kosbahn and T Baier and J Reitenbach and Q Zhong and A Vagias and R Cubitt and N Chaulagain and K Shankar and H \"{U}bele and K Krischer and P M\"{u}ller-Buschbaum},
url = {\<Go to ISI\>://WOS:001561038000001},
doi = {10.1002/cssc.202501550},
issn = {1864-5631},
year = {2025},
date = {2025-09-01},
journal = {Chemsuschem},
abstract = {Photocatalytic water splitting enables the generation of green hydrogen (H2). In this framework, water and sunlight are the sustainable sources. Photocatalyst-loaded hydrogel materials have already shown their potential as a water storage and catalyst host matrix for H2 production. This study explores the thin film geometry of such systems to demonstrate the scalability of photocatalysis. Graphitic carbon nitride is used as a catalyst and combined with platinum as a co-catalyst. The resulting catalytic centers are introduced in poly(N-isopropylacrylamide) hydrogel thin films. First, the swelling behavior of the resulting hybrid hydrogels is studied under high relative humidity, and the influence of different catalyst loadings is discussed. Then, time-of-flight neutron reflectometry is used to access the vertical material composition inside the hybrid thin film in the dry state, which shows an enrichment layer of catalyst at the substrate-bulk interface. Operando grazing incidence small-angle neutron scattering displays the microscopic changes happening under heavy water (D2O) vapor and light irradiation. Next, gas chromatography demonstrates the potential of the studied hydrogel films by determining their H2 production rates. The recorded H2 production is correlated to the microstructure analysis and reveals the importance of the observed catalyst enrichment layer.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Photocatalytic water splitting enables the generation of green hydrogen (H2). In this framework, water and sunlight are the sustainable sources. Photocatalyst-loaded hydrogel materials have already shown their potential as a water storage and catalyst host matrix for H2 production. This study explores the thin film geometry of such systems to demonstrate the scalability of photocatalysis. Graphitic carbon nitride is used as a catalyst and combined with platinum as a co-catalyst. The resulting catalytic centers are introduced in poly(N-isopropylacrylamide) hydrogel thin films. First, the swelling behavior of the resulting hybrid hydrogels is studied under high relative humidity, and the influence of different catalyst loadings is discussed. Then, time-of-flight neutron reflectometry is used to access the vertical material composition inside the hybrid thin film in the dry state, which shows an enrichment layer of catalyst at the substrate-bulk interface. Operando grazing incidence small-angle neutron scattering displays the microscopic changes happening under heavy water (D2O) vapor and light irradiation. Next, gas chromatography demonstrates the potential of the studied hydrogel films by determining their H2 production rates. The recorded H2 production is correlated to the microstructure analysis and reveals the importance of the observed catalyst enrichment layer.
1315.
S Amzil, Y Y Xiao, D H Ma, J P Li, T H Xu, Z Z Ru, L H Cao, M Yang, S Y Luo, M Q Wu, M L Peng, Y H Li, S Tian, J Gao, Y Yu, P Müller-Buschbaum, T Cai, F Zhao, Q Li, Y J Cheng, Y G Xia
In: Materials Science & Engineering R-Reports, Bd. 166, 2025, ISSN: 0927-796X.
@article{nokey,
title = {Interfacial and solvent dehydrogenation engineering enables long-life high-voltage lithium-ion batteries},
author = {S Amzil and Y Y Xiao and D H Ma and J P Li and T H Xu and Z Z Ru and L H Cao and M Yang and S Y Luo and M Q Wu and M L Peng and Y H Li and S Tian and J Gao and Y Yu and P M\"{u}ller-Buschbaum and T Cai and F Zhao and Q Li and Y J Cheng and Y G Xia},
url = {\<Go to ISI\>://WOS:001523364200001},
doi = {10.1016/j.mser.2025.101051},
issn = {0927-796X},
year = {2025},
date = {2025-09-01},
journal = {Materials Science \& Engineering R-Reports},
volume = {166},
abstract = {High-voltage lithium-ion batteries (LIBs) using LiNi0.8Mn0.1Co0.1O2 (NCM811) cathode materials present a promising avenue for increasing energy density. However, achieving stable operation at elevated voltages is hindered by chemical instability in ethylene carbonate (EC)-based electrolytes, leading to parasitic interfacial reactions. Herein, we introduce 2-hydroxy-5-nitro-3-(trifluoromethyl) pyridine (HNTFP) as a multifunctional electrolyte additive to mitigate EC dehydrogenation and minimize interfacial side reactions. Leveraging the unique functional groups of HNTFP (NO2, CF3, and C\textendashO), we demonstrate the formation of a robust hybrid/ inorganic cathode electrolyte interphase (CEI) on high-voltage cathodes and a fluorine-rich solid electrolyte interphase (SEI) on graphite anodes. These interphases enable 4.5 V-charged NCM811||graphite full cells to achieve a capacity retention of 92 % over 500 cycles, while commercial 1 Ah pouch cells retain 89 % over 1000 cycles. This study provides a fresh perspective on electrolyte additive design and underscores the transformative potential of HNTFP in enabling long-life, high-voltage LIBs with superior stability and performance.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
High-voltage lithium-ion batteries (LIBs) using LiNi0.8Mn0.1Co0.1O2 (NCM811) cathode materials present a promising avenue for increasing energy density. However, achieving stable operation at elevated voltages is hindered by chemical instability in ethylene carbonate (EC)-based electrolytes, leading to parasitic interfacial reactions. Herein, we introduce 2-hydroxy-5-nitro-3-(trifluoromethyl) pyridine (HNTFP) as a multifunctional electrolyte additive to mitigate EC dehydrogenation and minimize interfacial side reactions. Leveraging the unique functional groups of HNTFP (NO2, CF3, and C–O), we demonstrate the formation of a robust hybrid/ inorganic cathode electrolyte interphase (CEI) on high-voltage cathodes and a fluorine-rich solid electrolyte interphase (SEI) on graphite anodes. These interphases enable 4.5 V-charged NCM811||graphite full cells to achieve a capacity retention of 92 % over 500 cycles, while commercial 1 Ah pouch cells retain 89 % over 1000 cycles. This study provides a fresh perspective on electrolyte additive design and underscores the transformative potential of HNTFP in enabling long-life, high-voltage LIBs with superior stability and performance.
1314.
T Höldrich, A Wieland, F Pantle, J Winnerl, M Stutzmann
Selective growth and characterization of GaN nanowires on SiC substrates Artikel
In: Journal of Crystal Growth, Bd. 665, S. 128194, 2025, ISSN: 0022-0248.
@article{nokey,
title = {Selective growth and characterization of GaN nanowires on SiC substrates},
author = {T H\"{o}ldrich and A Wieland and F Pantle and J Winnerl and M Stutzmann},
url = {https://www.sciencedirect.com/science/article/pii/S0022024825001423},
doi = {https://doi.org/10.1016/j.jcrysgro.2025.128194},
issn = {0022-0248},
year = {2025},
date = {2025-09-01},
journal = {Journal of Crystal Growth},
volume = {665},
pages = {128194},
abstract = {GaN on SiC is a promising material combination for high power devices, where especially nanostructures, such as nanowires or nanofins, are a space and resource saving solution. In this work we demonstrate the selective area growth of GaN nanowires on SiC substrates, using the polytype 6H-SiC. We investigate the influence of the Si- and C-polarity of the substrate on the structural properties of the GaN nanowires by scanning electron microscopy and photoluminescence spectroscopy. On both substrates uniform and hexagonal nanowires are achieved for the respective optimal growth temperature, which is determined to be 20$circ $C higher for Si-polarity. As the polarity combination of the SiC substrate and GaN nanowires strongly influences the electrical properties at the heterointerface due to different charge accumulations, it is necessary to investigate the epitaxial relationship. X-ray diffraction revealed that the GaN nanowires exclusively adopt the orientation of the underlying SiC lattice, leading to an in-plane epitaxial relationship of (11¯00)GaN/(11¯00)6H-SiC. Polarity-selective wet chemical etching and Kelvin probe force microscopy showed that the GaN nanowires preserve the polarity of the substrate, thus, either a predominantly metal-polar (Si-polar/Ga-polar) or non-metal-polar (C-polar/N-polar) orientation is present. The complete epitaxial relationship on both substrate polarities can be identified as (11¯00)[0001]GaN||(11¯00)[0001]6H-SiC for the large majority of NWs at their respective optimum growth temperatures.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
GaN on SiC is a promising material combination for high power devices, where especially nanostructures, such as nanowires or nanofins, are a space and resource saving solution. In this work we demonstrate the selective area growth of GaN nanowires on SiC substrates, using the polytype 6H-SiC. We investigate the influence of the Si- and C-polarity of the substrate on the structural properties of the GaN nanowires by scanning electron microscopy and photoluminescence spectroscopy. On both substrates uniform and hexagonal nanowires are achieved for the respective optimal growth temperature, which is determined to be 20$circ $C higher for Si-polarity. As the polarity combination of the SiC substrate and GaN nanowires strongly influences the electrical properties at the heterointerface due to different charge accumulations, it is necessary to investigate the epitaxial relationship. X-ray diffraction revealed that the GaN nanowires exclusively adopt the orientation of the underlying SiC lattice, leading to an in-plane epitaxial relationship of (11¯00)GaN/(11¯00)6H-SiC. Polarity-selective wet chemical etching and Kelvin probe force microscopy showed that the GaN nanowires preserve the polarity of the substrate, thus, either a predominantly metal-polar (Si-polar/Ga-polar) or non-metal-polar (C-polar/N-polar) orientation is present. The complete epitaxial relationship on both substrate polarities can be identified as (11¯00)[0001]GaN||(11¯00)[0001]6H-SiC for the large majority of NWs at their respective optimum growth temperatures.
1313.
S M Qian, A T S Freiberg, F Friedrich, C Grön, H A Gasteiger
Simulating Electrochemical Aging in NCM111 Materials Through Controlled Chemical Delithiation Artikel
In: Journal of the Electrochemical Society, Bd. 172, Nr. 8, 2025, ISSN: 0013-4651.
@article{nokey,
title = {Simulating Electrochemical Aging in NCM111 Materials Through Controlled Chemical Delithiation},
author = {S M Qian and A T S Freiberg and F Friedrich and C Gr\"{o}n and H A Gasteiger},
url = {\<Go to ISI\>://WOS:001559898400001},
doi = {10.1149/1945-7111/adfca2},
issn = {0013-4651},
year = {2025},
date = {2025-08-28},
journal = {Journal of the Electrochemical Society},
volume = {172},
number = {8},
abstract = {To meet the cycle life requirements and to guarantee the safe operation of lithium-ion batteries, the upper cutoff potential of cathode active materials based on mixed transition metal layered oxides like NCM (LiMO2, with M = Ni, Co, Mn) must be restricted, thereby limiting the available specific capacity. A significant degradation mechanism in NCM materials involves the harmful release of lattice oxygen at high degrees of delithiation (reached at high cathode potentials), forming an oxygen-depleted surface phase on the active material particles accompanied by electrolyte oxidation. To mimic the electrochemically-induced lattice oxygen release, NCM materials can be subjected to chemical delithiation and subsequent heat-treatment. We thus investigated the chemical delithiation of NCM111 (Li1.0(Ni1/3Co1/3Mn1/3)O2) with NO2BF4, followed by a heat-treatment. The resulting materials are characterized with regards to their electrochemical characteristics as well as by thermogravimetric analysis-mass spectrometry, X-ray diffraction, scanning electron microscopy, and gas adsorption analysis. We discovered that chemical delithiation initially produces a disordered layered phase that is electrochemically less active. Upon heat-treatment, this phase restructures into a fully-lithiated and well-ordered layered phase and an electrochemically inactive spinel phase. This study enhances our understanding of the phases that form when NCM materials undergo extensive delithiation.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
To meet the cycle life requirements and to guarantee the safe operation of lithium-ion batteries, the upper cutoff potential of cathode active materials based on mixed transition metal layered oxides like NCM (LiMO2, with M = Ni, Co, Mn) must be restricted, thereby limiting the available specific capacity. A significant degradation mechanism in NCM materials involves the harmful release of lattice oxygen at high degrees of delithiation (reached at high cathode potentials), forming an oxygen-depleted surface phase on the active material particles accompanied by electrolyte oxidation. To mimic the electrochemically-induced lattice oxygen release, NCM materials can be subjected to chemical delithiation and subsequent heat-treatment. We thus investigated the chemical delithiation of NCM111 (Li1.0(Ni1/3Co1/3Mn1/3)O2) with NO2BF4, followed by a heat-treatment. The resulting materials are characterized with regards to their electrochemical characteristics as well as by thermogravimetric analysis-mass spectrometry, X-ray diffraction, scanning electron microscopy, and gas adsorption analysis. We discovered that chemical delithiation initially produces a disordered layered phase that is electrochemically less active. Upon heat-treatment, this phase restructures into a fully-lithiated and well-ordered layered phase and an electrochemically inactive spinel phase. This study enhances our understanding of the phases that form when NCM materials undergo extensive delithiation.
1312.
T Jiang, A Bhattacharya, M Barkey, A Aigner, L Rohrer, T Weber, J Wang, S A Maier, A Tittl
In: Advanced Functional Materials, 2025, ISSN: 1616-301X.
@article{nokey,
title = {A Comparative Analysis of Plasmonic and Dielectric Metasurface Sensing Platforms Powered by Bound States in the Continuum},
author = {T Jiang and A Bhattacharya and M Barkey and A Aigner and L Rohrer and T Weber and J Wang and S A Maier and A Tittl},
url = {\<Go to ISI\>://WOS:001558957300001},
doi = {10.1002/adfm.202516021},
issn = {1616-301X},
year = {2025},
date = {2025-08-28},
journal = {Advanced Functional Materials},
abstract = {Nanophotonic platforms based on surface-enhanced infrared absorbance spectroscopy (SEIRAS) have emerged as an effective tool for molecular detection. Sensitive nanophotonic sensors with robust resonant modes and amplified electromagnetic near fields are essential for spectroscopy, especially in lossy environments. Metasurfaces driven by bound state in the continuum (BICs) have unlocked a powerful platform for molecular detection due to their exceptional spectral selectivity. While plasmonic BIC metasurfaces are preferred for molecular spectroscopy due to their high surface fields, enhancing the interaction with analytes, dielectric BICs have become popular due to their high-quality factors and, thus, high sensitivity. However, their sensing performance has largely been demonstrated in air, neglecting the intrinsic infrared (IR) losses found in common solvents. This study evaluates the suitability of plasmonic versus dielectric platforms for in situ molecular spectroscopy. Here, the sensing performance of plasmonic (gold) and dielectric (silicon) metasurfaces is assessed across liquid environments with varying losses resembling typical solvents. The results show that dielectric metasurfaces excel in dry conditions, while plasmonic BIC metasurfaces outperform them in lossy solvents, with a distinct crossover point where both show similar performance. The results provide a framework for selecting the optimal metasurface material platform for SEIRAS studies based on environmental conditions.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Nanophotonic platforms based on surface-enhanced infrared absorbance spectroscopy (SEIRAS) have emerged as an effective tool for molecular detection. Sensitive nanophotonic sensors with robust resonant modes and amplified electromagnetic near fields are essential for spectroscopy, especially in lossy environments. Metasurfaces driven by bound state in the continuum (BICs) have unlocked a powerful platform for molecular detection due to their exceptional spectral selectivity. While plasmonic BIC metasurfaces are preferred for molecular spectroscopy due to their high surface fields, enhancing the interaction with analytes, dielectric BICs have become popular due to their high-quality factors and, thus, high sensitivity. However, their sensing performance has largely been demonstrated in air, neglecting the intrinsic infrared (IR) losses found in common solvents. This study evaluates the suitability of plasmonic versus dielectric platforms for in situ molecular spectroscopy. Here, the sensing performance of plasmonic (gold) and dielectric (silicon) metasurfaces is assessed across liquid environments with varying losses resembling typical solvents. The results show that dielectric metasurfaces excel in dry conditions, while plasmonic BIC metasurfaces outperform them in lossy solvents, with a distinct crossover point where both show similar performance. The results provide a framework for selecting the optimal metasurface material platform for SEIRAS studies based on environmental conditions.
1311.
R Jayabalan, G K Hanumantharaju, T Hettiger, A Sarkar, F S Zu, A Ullrich, A Abfalterer, A S Urban, N Koch, D Andrienko, M Scheele, W Brütting
In: Advanced Optical Materials, 2025, ISSN: 2195-1071.
@article{nokey,
title = {Optimizing Carrier Balance in CsPbBr3 Nanocrystal LEDs: The Role of Alkyl Ligands and Polar Electron Transport Layers},
author = {R Jayabalan and G K Hanumantharaju and T Hettiger and A Sarkar and F S Zu and A Ullrich and A Abfalterer and A S Urban and N Koch and D Andrienko and M Scheele and W Br\"{u}tting},
url = {\<Go to ISI\>://WOS:001556372500001},
doi = {10.1002/adom.202501361},
issn = {2195-1071},
year = {2025},
date = {2025-08-26},
journal = {Advanced Optical Materials},
abstract = {The study of lead halide perovskite nanocrystal based light-emitting diodes (LEDs) has advanced significantly, with notable improvements in stability and optical properties. However, optimizing charge carrier injection and transport remains a challenge. Efficient electroluminescence requires a balanced transport of both holes and electrons within the emitting material. Here, cubic CsPbBr3 nanocrystals passivated with oleylamine and oleic acid are investigated, comparing them to ligand-exchanged nanocrystals with didodecyldimethylammonium bromide (DDABr). Nuclear magnetic resonance spectroscopy and transmission electron microscopy confirm successful ligand exchange, revealing reduced ligand coverage in DDABr-treated nanocrystals. Photoelectron spectroscopy, spectroelectrochemistry, and single-carrier devices indicate improved hole injection in DDABr-capped nanocrystals. Density functional theory calculations further reveal the influence of ligand type and coverage on energy levels, with oleic acid introducing localized states in native nanocrystals. Additionally, incorporation of a polar electron transport layer enhances LED performance by over an order of magnitude in DDABr-capped nanocrystals, driven by improved charge balance arising from the spontaneous orientation polarization of the electron transport layer. These findings highlight the critical role of ligand selection, passivation degree, and charge transport control by the adjacent organic transport layers in optimizing LED efficiency.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The study of lead halide perovskite nanocrystal based light-emitting diodes (LEDs) has advanced significantly, with notable improvements in stability and optical properties. However, optimizing charge carrier injection and transport remains a challenge. Efficient electroluminescence requires a balanced transport of both holes and electrons within the emitting material. Here, cubic CsPbBr3 nanocrystals passivated with oleylamine and oleic acid are investigated, comparing them to ligand-exchanged nanocrystals with didodecyldimethylammonium bromide (DDABr). Nuclear magnetic resonance spectroscopy and transmission electron microscopy confirm successful ligand exchange, revealing reduced ligand coverage in DDABr-treated nanocrystals. Photoelectron spectroscopy, spectroelectrochemistry, and single-carrier devices indicate improved hole injection in DDABr-capped nanocrystals. Density functional theory calculations further reveal the influence of ligand type and coverage on energy levels, with oleic acid introducing localized states in native nanocrystals. Additionally, incorporation of a polar electron transport layer enhances LED performance by over an order of magnitude in DDABr-capped nanocrystals, driven by improved charge balance arising from the spontaneous orientation polarization of the electron transport layer. These findings highlight the critical role of ligand selection, passivation degree, and charge transport control by the adjacent organic transport layers in optimizing LED efficiency.
1310.
C Panagiotopoulou, S P Liu, J Pittrich, H Iglev, F Deschler, A Kartouzian
Chiroptical Amplification Beyond Enantiopurity in Chiral Films Artikel
In: Advanced Optical Materials, Bd. 13, Nr. 29, 2025, ISSN: 2195-1071.
@article{nokey,
title = {Chiroptical Amplification Beyond Enantiopurity in Chiral Films},
author = {C Panagiotopoulou and S P Liu and J Pittrich and H Iglev and F Deschler and A Kartouzian},
url = {\<Go to ISI\>://WOS:001585443000001},
doi = {10.1002/adom.202501895},
issn = {2195-1071},
year = {2025},
date = {2025-08-24},
journal = {Advanced Optical Materials},
volume = {13},
number = {29},
abstract = {Chiral films are key functional materials for spintronics, enantioselective sensing, and chiral photonics. Understanding and controlling chiroptical activity in such materials is crucial for advancing next-generation photonic and spintronic technologies. A widely held belief is that enantiopure systems inherently offer the strongest chiroptical responses. In this perspective, this assumption is questioned by drawing attention to nonlinear dependencies between normalized chiroptical response as given by the anisotropy factor, g, and enantiomeric excess (ee) in thin-film systems. Using 2D and 1D chiral hybrid metal-halide perovskites as testbeds, it is shown that the highest optical activity often emerges at intermediate ee values - far from the enantiopure limit. Also, for tryptophan (a chiral amino acid), a similar response is observed. This behavior points to complex structural reorganizations and interaction patterns in chiral films. The common practice of limiting chiroptical measurements on chiral films to racemic and enantiopure samples overlooks a rich, informative regime is believed. Systematic g-ee profiling is proposed as a standard part of the experimental workflow in chiral materials research, which can reveal underexplored material spaces and enable more deliberate control of chiroptical properties.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Chiral films are key functional materials for spintronics, enantioselective sensing, and chiral photonics. Understanding and controlling chiroptical activity in such materials is crucial for advancing next-generation photonic and spintronic technologies. A widely held belief is that enantiopure systems inherently offer the strongest chiroptical responses. In this perspective, this assumption is questioned by drawing attention to nonlinear dependencies between normalized chiroptical response as given by the anisotropy factor, g, and enantiomeric excess (ee) in thin-film systems. Using 2D and 1D chiral hybrid metal-halide perovskites as testbeds, it is shown that the highest optical activity often emerges at intermediate ee values - far from the enantiopure limit. Also, for tryptophan (a chiral amino acid), a similar response is observed. This behavior points to complex structural reorganizations and interaction patterns in chiral films. The common practice of limiting chiroptical measurements on chiral films to racemic and enantiopure samples overlooks a rich, informative regime is believed. Systematic g-ee profiling is proposed as a standard part of the experimental workflow in chiral materials research, which can reveal underexplored material spaces and enable more deliberate control of chiroptical properties.
1309.
S L Wang, H Lian, H F Ling, H Wu, T X Xiao, Y J Huang, P Müller-Buschbaum
Emerging low-dimensional perovskite resistive switching memristors: from fundamentals to devices Artikel
In: Opto-Electronic Advances, Bd. 8, Nr. 8, 2025, ISSN: 2096-4579.
@article{nokey,
title = {Emerging low-dimensional perovskite resistive switching memristors: from fundamentals to devices},
author = {S L Wang and H Lian and H F Ling and H Wu and T X Xiao and Y J Huang and P M\"{u}ller-Buschbaum},
url = {\<Go to ISI\>://WOS:001558650900003},
doi = {10.29026/oea.2025.240316},
issn = {2096-4579},
year = {2025},
date = {2025-08-24},
journal = {Opto-Electronic Advances},
volume = {8},
number = {8},
abstract = {With the exponential growth of the internet of things, artificial intelligence, and energy-efficient high-volume data digital communications, there is an urgent demand to develop new information technologies with high storage capacity. This needs to address the looming challenge of conventional Von Neumann architecture and Moore's law bottleneck for future data-intensive computing applications. A promising remedy lies in memristors, which offer distinct advantages of scalability, rapid access times, stable data retention, low power consumption, multistate storage capability and fast operation. Among the various materials used for active layers in memristors, low dimensional perovskite semiconductors with structural diversity and superior stability exhibit great potential for next generation memristor applications, leveraging hysteresis characteristics caused by ion migration and defects. In this review the progress of low-dimensional perovskite memory devices is comprehensively summarized. The working mechanism and fundamental processes, including ion migration dynamics, charge carrier transport and electronic resistance that underlies the switching behavior of memristors are discussed. Additionally, the device parameters are analyzed with special focus on the effective methods to improve electrical performance and operational stability. Finally, the challenges and perspective on major hurdles of low-dimensional perovskite memristors in the expansive application domains are provided.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
With the exponential growth of the internet of things, artificial intelligence, and energy-efficient high-volume data digital communications, there is an urgent demand to develop new information technologies with high storage capacity. This needs to address the looming challenge of conventional Von Neumann architecture and Moore's law bottleneck for future data-intensive computing applications. A promising remedy lies in memristors, which offer distinct advantages of scalability, rapid access times, stable data retention, low power consumption, multistate storage capability and fast operation. Among the various materials used for active layers in memristors, low dimensional perovskite semiconductors with structural diversity and superior stability exhibit great potential for next generation memristor applications, leveraging hysteresis characteristics caused by ion migration and defects. In this review the progress of low-dimensional perovskite memory devices is comprehensively summarized. The working mechanism and fundamental processes, including ion migration dynamics, charge carrier transport and electronic resistance that underlies the switching behavior of memristors are discussed. Additionally, the device parameters are analyzed with special focus on the effective methods to improve electrical performance and operational stability. Finally, the challenges and perspective on major hurdles of low-dimensional perovskite memristors in the expansive application domains are provided.
1308.
L Camuti, S Kim, F Podjaski, M Vega-Paredes, A M Mingers, T Acartürk, U Starke, B V Lotsch, C Scheu, B Gault, S Y Zhang
Phase-Stable Palladium Hydride Derived from PdCoO2 for Sustainable Hydrogen Evolution Reaction Artikel
In: Advanced Functional Materials, 2025, ISSN: 1616-301X.
@article{nokey,
title = {Phase-Stable Palladium Hydride Derived from PdCoO2 for Sustainable Hydrogen Evolution Reaction},
author = {L Camuti and S Kim and F Podjaski and M Vega-Paredes and A M Mingers and T Acart\"{u}rk and U Starke and B V Lotsch and C Scheu and B Gault and S Y Zhang},
url = {\<Go to ISI\>://WOS:001555162600001},
doi = {10.1002/adfm.202514366},
issn = {1616-301X},
year = {2025},
date = {2025-08-22},
journal = {Advanced Functional Materials},
abstract = {Active and reliable electrocatalysts are fundamental to renewable energy technologies. PdCoO2 is recently recognized as a promising catalyst template for the hydrogen evolution reaction (HER) in acidic media, thanks to the formation of exceptionally active PdHx. In this article, the transformation process of single PdCoO2 particles during HER is monitored and elucidated, confirming their almost complete transformation to PdHx. Using operando mass spectrometry, Co dissolution from the PdCoO2 template is observed under reductive potentials, with a partial current of 0.1% of the HER current, while PdHx is formed simultaneously. High HER activity of this phase is retained with long-term operation, dry storage, or vacuum exposure. Isotope labeling of hydrogen using D2O confirms the formation of a stable PdHx phase by secondary ion mass spectrometry and down to the near-atomic scale by atom probe tomography. A separation between D-poor alpha- and D-rich beta-Pd hydrides is observed with an overall composition of beta-PdD0.64. These findings highlight the critical role of a templated growth method for obtaining stabilized PdHx, enabling Pt-like efficient HER without the commonly slow activation processes observed in Pd due to rate-limiting material hydrogenation. This offer insights into the design of more efficient electrocatalysts for renewable energy technologies.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Active and reliable electrocatalysts are fundamental to renewable energy technologies. PdCoO2 is recently recognized as a promising catalyst template for the hydrogen evolution reaction (HER) in acidic media, thanks to the formation of exceptionally active PdHx. In this article, the transformation process of single PdCoO2 particles during HER is monitored and elucidated, confirming their almost complete transformation to PdHx. Using operando mass spectrometry, Co dissolution from the PdCoO2 template is observed under reductive potentials, with a partial current of 0.1% of the HER current, while PdHx is formed simultaneously. High HER activity of this phase is retained with long-term operation, dry storage, or vacuum exposure. Isotope labeling of hydrogen using D2O confirms the formation of a stable PdHx phase by secondary ion mass spectrometry and down to the near-atomic scale by atom probe tomography. A separation between D-poor alpha- and D-rich beta-Pd hydrides is observed with an overall composition of beta-PdD0.64. These findings highlight the critical role of a templated growth method for obtaining stabilized PdHx, enabling Pt-like efficient HER without the commonly slow activation processes observed in Pd due to rate-limiting material hydrogenation. This offer insights into the design of more efficient electrocatalysts for renewable energy technologies.
1307.
L Sandoval-Díaz, R Blume, K Dembélé, J Folke, M Boniface, F Girgsdies, A Hammud, Z Gheisari, D Ivanov, R Eckert, S Reitmeier, A Reitzmann, R Schlögl, B R Cuenya, H Ruland, A Knop-Gericke, T Lunkenbein
Decoding technical multi-promoted ammonia synthesis catalysts Artikel
In: Nature Communications, Bd. 16, Nr. 1, 2025.
@article{nokey,
title = {Decoding technical multi-promoted ammonia synthesis catalysts},
author = {L Sandoval-D\'{i}az and R Blume and K Demb\'{e}l\'{e} and J Folke and M Boniface and F Girgsdies and A Hammud and Z Gheisari and D Ivanov and R Eckert and S Reitmeier and A Reitzmann and R Schl\"{o}gl and B R Cuenya and H Ruland and A Knop-Gericke and T Lunkenbein},
url = {\<Go to ISI\>://WOS:001559618600018},
doi = {10.1038/s41467-025-63061-6},
year = {2025},
date = {2025-08-21},
journal = {Nature Communications},
volume = {16},
number = {1},
abstract = {Ammonia is industrially produced by the Haber-Bosch process over a fused, multi-promoted iron-based catalyst. Current knowledge about the reaction has been derived from model systems of reduced structural complexity, impeding any clear-cut structure-activity correlation relevant for the industrial counterpart. Here, we unveil the structural evolution of complex, technical, multi-promoted ammonia synthesis catalysts by operando scanning electron microscopy and near-ambient pressure X-ray photoelectron spectroscopy. We highlight that the activation is the critical step in which the catalyst is formed and decode the pivotal role of the promoters. We discover that the active structure consists of a nanodispersion of Fe covered by mobile K-containing adsorbates, so called "ammonia K". The porous catalyst is stabilized by mineral cementitious phases containing oxides of Al, Si, Ca, and Fe. The synergism between the different promoters contributes simultaneously to the structural stability, hierarchical architecture, catalytic activity, and poisoning resistance. The confluence of these aspects is the key for the superior performance of technical catalyst formulations.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Ammonia is industrially produced by the Haber-Bosch process over a fused, multi-promoted iron-based catalyst. Current knowledge about the reaction has been derived from model systems of reduced structural complexity, impeding any clear-cut structure-activity correlation relevant for the industrial counterpart. Here, we unveil the structural evolution of complex, technical, multi-promoted ammonia synthesis catalysts by operando scanning electron microscopy and near-ambient pressure X-ray photoelectron spectroscopy. We highlight that the activation is the critical step in which the catalyst is formed and decode the pivotal role of the promoters. We discover that the active structure consists of a nanodispersion of Fe covered by mobile K-containing adsorbates, so called "ammonia K". The porous catalyst is stabilized by mineral cementitious phases containing oxides of Al, Si, Ca, and Fe. The synergism between the different promoters contributes simultaneously to the structural stability, hierarchical architecture, catalytic activity, and poisoning resistance. The confluence of these aspects is the key for the superior performance of technical catalyst formulations.
1306.
L Z Liu, M Z Hussain, D Lei, O Henrotte, E Cortes, A S Bandarenka, R A Fischer
In: Advanced Science, 2025.
@article{nokey,
title = {Cobalt-Based Catalyst Integration Into a Hierarchically Ordered Macro-Meso-microporous Carbon Cathode for High-performance Aqueous Zn-Sulfur Batteries},
author = {L Z Liu and M Z Hussain and D Lei and O Henrotte and E Cortes and A S Bandarenka and R A Fischer},
url = {\<Go to ISI\>://WOS:001554583800001},
doi = {10.1002/advs.202509945},
year = {2025},
date = {2025-08-21},
journal = {Advanced Science},
abstract = {The pyrolytic synthesis of an ordered macro-meso-micro porous carbon cathode material (OM-PC) with integration of a Co3ZnC/Co catalyst is reported. It is derived from a Co-doped ZIF-8 framework via a templated in situ growth within the interstitial spaces of a preformed self-assembled polystyrene monolith, followed by the template removal. The hierarchical 3D architecture facilitates Zn2(+) diffusion and enhances reaction kinetics during charge-discharge processes. The integrated Co3ZnC/Co catalyst significantly improves the surface affinity of the porous carbon host for polysulfide trapping and accelerates polysulfide redox conversion, leading to enhanced sulfur utilization, mitigated shuttle effects, and longer cycling stability. The fabricated aqueous Zn-S battery with the sulfur-loaded cathode denoted as S@Co3ZnC/Co/OM-PC delivers a synergistic high discharge capacity of approximate to 1685 mA h g-1, which includes approximate to 115 mA h g-1 contributed from the I3 -/I- redox couple. The device shows low polarization and exhibits a minimal capacity decay of approximate to 0.027% per cycle over 400 cycles. It maintained a good rate performance of approximate to 1035 mA h g-1 at 3 A g-1, with long cycling stability. In-depth investigation reveals a multistep intermediate polysulfides conversion pathway in the aqueous electrolyte, which effectively avoids the sluggish solid-solid conversion.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The pyrolytic synthesis of an ordered macro-meso-micro porous carbon cathode material (OM-PC) with integration of a Co3ZnC/Co catalyst is reported. It is derived from a Co-doped ZIF-8 framework via a templated in situ growth within the interstitial spaces of a preformed self-assembled polystyrene monolith, followed by the template removal. The hierarchical 3D architecture facilitates Zn2(+) diffusion and enhances reaction kinetics during charge-discharge processes. The integrated Co3ZnC/Co catalyst significantly improves the surface affinity of the porous carbon host for polysulfide trapping and accelerates polysulfide redox conversion, leading to enhanced sulfur utilization, mitigated shuttle effects, and longer cycling stability. The fabricated aqueous Zn-S battery with the sulfur-loaded cathode denoted as S@Co3ZnC/Co/OM-PC delivers a synergistic high discharge capacity of approximate to 1685 mA h g-1, which includes approximate to 115 mA h g-1 contributed from the I3 -/I- redox couple. The device shows low polarization and exhibits a minimal capacity decay of approximate to 0.027% per cycle over 400 cycles. It maintained a good rate performance of approximate to 1035 mA h g-1 at 3 A g-1, with long cycling stability. In-depth investigation reveals a multistep intermediate polysulfides conversion pathway in the aqueous electrolyte, which effectively avoids the sluggish solid-solid conversion.
1305.
A Buyan-Arivjikh, J Fricker, T Baier, X J Ci, L X Li, D Gaur, L Polavarapu, M Schwartzkopf, S K Vayalil, P Mueller-Buschbaum
In: Small, 2025, ISSN: 1613-6810.
@article{nokey,
title = {CsPbBr3 Nanocrystals as Bottom Interface Nucleation Seeds for Printing Oriented FAPbI3 Thin Films: An In Situ Study},
author = {A Buyan-Arivjikh and J Fricker and T Baier and X J Ci and L X Li and D Gaur and L Polavarapu and M Schwartzkopf and S K Vayalil and P Mueller-Buschbaum},
url = {\<Go to ISI\>://WOS:001552870900001},
doi = {10.1002/smll.202505895},
issn = {1613-6810},
year = {2025},
date = {2025-08-20},
journal = {Small},
abstract = {The exceptional optoelectronic properties of lead halide perovskites are highly sensitive to processing conditions, as uncontrolled crystallization driven by random nucleation often results in defect-rich active layers that impair device performance. Achieving controlled and oriented crystallization in printed films remains a major challenge. To address this, we introduce a pre-deposited CsPbBr3 nanocrystal seed layer at the bottom interface to guide crystallization and suppress defect formation. This strategy is evaluated via an in situ study on FAPbI3, offering mechanistic insights into the influence of seeding on film growth and optoelectronic quality. Using in situ grazing-incidence wide-angle X-ray scattering, transmission-mode UV-vis absorption, and photoluminescence spectroscopy, phase evolution and seed-mediated growth kinetics are tracked. Seeding accelerates the transition from the photoinactive delta-phase to the photoactive alpha-phase, yielding a crystallization rate constant over six times higher than in unseeded films. Moreover, the seed layer governs the crystallographic orientation of the resulting perovskite film, leading to improved optical absorption and reduced defect density.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The exceptional optoelectronic properties of lead halide perovskites are highly sensitive to processing conditions, as uncontrolled crystallization driven by random nucleation often results in defect-rich active layers that impair device performance. Achieving controlled and oriented crystallization in printed films remains a major challenge. To address this, we introduce a pre-deposited CsPbBr3 nanocrystal seed layer at the bottom interface to guide crystallization and suppress defect formation. This strategy is evaluated via an in situ study on FAPbI3, offering mechanistic insights into the influence of seeding on film growth and optoelectronic quality. Using in situ grazing-incidence wide-angle X-ray scattering, transmission-mode UV-vis absorption, and photoluminescence spectroscopy, phase evolution and seed-mediated growth kinetics are tracked. Seeding accelerates the transition from the photoinactive delta-phase to the photoactive alpha-phase, yielding a crystallization rate constant over six times higher than in unseeded films. Moreover, the seed layer governs the crystallographic orientation of the resulting perovskite film, leading to improved optical absorption and reduced defect density.
1304.
Y J Guo, G J Pan, S Tu, Y Bulut, J G Zhou, A Jeromin, T F Keller, A Stierle, G Nemeth, F Borondics, B Sochor, S K Vayalil, L D Söderberg, P Müller-Buschbaum, S V Roth
In: Advanced Functional Materials, 2025, ISSN: 1616-301X.
@article{nokey,
title = {Biopolymer-Templated Hierarchical 3D-Structured Gold Nanoparticle/Graphene Oxide Hybrid Materials for Ultrasensitive Surface-Enhanced Raman Scattering},
author = {Y J Guo and G J Pan and S Tu and Y Bulut and J G Zhou and A Jeromin and T F Keller and A Stierle and G Nemeth and F Borondics and B Sochor and S K Vayalil and L D S\"{o}derberg and P M\"{u}ller-Buschbaum and S V Roth},
url = {\<Go to ISI\>://WOS:001552302100001},
doi = {10.1002/adfm.202515801},
issn = {1616-301X},
year = {2025},
date = {2025-08-19},
journal = {Advanced Functional Materials},
abstract = {Surface-enhanced Raman scattering (SERS) is a highly advantageous analytical technique for detecting trace biological and chemical compounds. However, significant challenges remain in the cost-effective fabrication of large-area and homogenous SERS substrates. A simple and scalable approach utilizing a layer-by-layer spray deposition followed by thermal annealing is proposed to fabricate cellulose nanofibril (CNF) films loaded with gold nanoparticles (Au NPs) and graphene oxide (GO) hybrids as SERS substrates. These hybrid 3D structures comprising CNF/Au NPs/GO significantly enhance SERS sensitivity by both electromagnetic enhancement and chemical enhancement. Incorporating CNF as a 3D network enables a more uniform distribution of Au NPs/GO. Thermal annealing further induces hotspots. For instance, the annealed CNF/Au NPs/GO hybrid thin films achieve a detection limit of 1.0 x 10-13 m and a high enhancement factor of 4.97 x 1011 for Rhodamine 6G. Grazing incidence small-angle X-ray scattering combined with nano-Fourier-transform infrared spectroscopy is first used to confirm the combined Raman enhancement mechanism of localized surface plasmon resonance and interface charge transfer with high spatial resolution. Therefore, the proposed methodology establishes a robust framework for the scalable fabrication of ultrasensitive SERS substrates.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Surface-enhanced Raman scattering (SERS) is a highly advantageous analytical technique for detecting trace biological and chemical compounds. However, significant challenges remain in the cost-effective fabrication of large-area and homogenous SERS substrates. A simple and scalable approach utilizing a layer-by-layer spray deposition followed by thermal annealing is proposed to fabricate cellulose nanofibril (CNF) films loaded with gold nanoparticles (Au NPs) and graphene oxide (GO) hybrids as SERS substrates. These hybrid 3D structures comprising CNF/Au NPs/GO significantly enhance SERS sensitivity by both electromagnetic enhancement and chemical enhancement. Incorporating CNF as a 3D network enables a more uniform distribution of Au NPs/GO. Thermal annealing further induces hotspots. For instance, the annealed CNF/Au NPs/GO hybrid thin films achieve a detection limit of 1.0 x 10-13 m and a high enhancement factor of 4.97 x 1011 for Rhodamine 6G. Grazing incidence small-angle X-ray scattering combined with nano-Fourier-transform infrared spectroscopy is first used to confirm the combined Raman enhancement mechanism of localized surface plasmon resonance and interface charge transfer with high spatial resolution. Therefore, the proposed methodology establishes a robust framework for the scalable fabrication of ultrasensitive SERS substrates.
1303.
H Y Zhang, W J Tian, J K Lin, P Zhang, G S Shao, S K Ravi, H Q Sun, E Cortés, V Andrei, S B Wang
Photosystem II-Carbon Nitride Photoanodes for Scalable Biophotoelectrochemistry Artikel
In: Advanced Materials, 2025, ISSN: 0935-9648.
@article{nokey,
title = {Photosystem II-Carbon Nitride Photoanodes for Scalable Biophotoelectrochemistry},
author = {H Y Zhang and W J Tian and J K Lin and P Zhang and G S Shao and S K Ravi and H Q Sun and E Cort\'{e}s and V Andrei and S B Wang},
url = {\<Go to ISI\>://WOS:001550386200001},
doi = {10.1002/adma.202508813},
issn = {0935-9648},
year = {2025},
date = {2025-08-15},
journal = {Advanced Materials},
abstract = {Photosystem II (PSII) is a vital photosynthetic enzyme with the potential for sustainable bioelectricity and fuel generation. However, interfacing PSII with intricate, small-scale electrodes for practical applications has been challenging. This study addresses this by creating protonated macroporous carbon nitride (MCN) as support and developing a scalable spray-freeze method to wire PSII with MCN. This facilitates the production of large-area MCN-PSII photoanodes up to 33 cm2 for biophotoelectrochemical water oxidation to O2, achieving efficient interfacial charge transfer and initial photocurrents in the mA range with Faradaic yield of 93.5 +/- 8.5% over 5 h. A bias-free biophotoelectrochemical (BPEC) device is designed by connecting the MCN-PSII photoanode to a carbon nanotube cathode loaded with bilirubin oxidase. An array of eight tandem BPEC cells with a photoactive area of 72 cm2 successfully powers low-power electronics, such as LEDs. This work paves an efficient way for bioelectrode fabrication, showcasing the potential of PSII-based semi-artificial systems for BPEC and biophotovoltaic applications.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Photosystem II (PSII) is a vital photosynthetic enzyme with the potential for sustainable bioelectricity and fuel generation. However, interfacing PSII with intricate, small-scale electrodes for practical applications has been challenging. This study addresses this by creating protonated macroporous carbon nitride (MCN) as support and developing a scalable spray-freeze method to wire PSII with MCN. This facilitates the production of large-area MCN-PSII photoanodes up to 33 cm2 for biophotoelectrochemical water oxidation to O2, achieving efficient interfacial charge transfer and initial photocurrents in the mA range with Faradaic yield of 93.5 +/- 8.5% over 5 h. A bias-free biophotoelectrochemical (BPEC) device is designed by connecting the MCN-PSII photoanode to a carbon nanotube cathode loaded with bilirubin oxidase. An array of eight tandem BPEC cells with a photoactive area of 72 cm2 successfully powers low-power electronics, such as LEDs. This work paves an efficient way for bioelectrode fabrication, showcasing the potential of PSII-based semi-artificial systems for BPEC and biophotovoltaic applications.
1302.
L G Balzat, Y Li, S Dums, I Moudrakovski, K Gjorgjevikj, A Schulz, Y H Li, S Krause, P Canepa, B V Lotsch
Structure and Transport Properties in the Pseudobinary Phase System Li4SiS4-Li4SnS4 Artikel
In: Chemistry of Materials, 2025, ISSN: 0897-4756.
@article{nokey,
title = {Structure and Transport Properties in the Pseudobinary Phase System Li4SiS4-Li4SnS4},
author = {L G Balzat and Y Li and S Dums and I Moudrakovski and K Gjorgjevikj and A Schulz and Y H Li and S Krause and P Canepa and B V Lotsch},
url = {\<Go to ISI\>://WOS:001551105400001},
doi = {10.1021/acs.chemmater.5c00358},
issn = {0897-4756},
year = {2025},
date = {2025-08-15},
journal = {Chemistry of Materials},
abstract = {Thio-lithium superionic conductors (thio-LISICONs) are a family of promising solid electrolyte materials for potential applications in solid-state batteries. The orthorhombic polymorph of the thio-LISICON Li4SiS4 (o-Li4SiS4) has been known for decades, but its complete crystal structure has been reported only recently. Here, using single-crystal X-ray diffraction, we reevaluated the crystal structure of o-Li4SiS4 and showed that o-Li4SiS4 crystallizes in space group Pmn21 (no. 31},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Thio-lithium superionic conductors (thio-LISICONs) are a family of promising solid electrolyte materials for potential applications in solid-state batteries. The orthorhombic polymorph of the thio-LISICON Li4SiS4 (o-Li4SiS4) has been known for decades, but its complete crystal structure has been reported only recently. Here, using single-crystal X-ray diffraction, we reevaluated the crystal structure of o-Li4SiS4 and showed that o-Li4SiS4 crystallizes in space group Pmn21 (no. 31
1301.
T L Zheng, M Q Wu, J W Xiong, M Yang, W Z Guo, Q H Zeng, H W Yu, T H Xu, W P Xie, Y Y Xiao, Z J Xu, Y X Liang, Z R Li, R X Qi, G J Pan, X T Shi, H B Zhao, X H Li, Y Y Xia, Y J Cheng, Y G Xia, P Müller-Buschbaum
In: Angewandte Chemie-International Edition, 2025.
@article{nokey,
title = {Anchoring and Competition: Weakly Solvated Structure of Glymes Enhances Stability in Lithium Metal Batteries Operating under Extreme Conditions},
author = {T L Zheng and M Q Wu and J W Xiong and M Yang and W Z Guo and Q H Zeng and H W Yu and T H Xu and W P Xie and Y Y Xiao and Z J Xu and Y X Liang and Z R Li and R X Qi and G J Pan and X T Shi and H B Zhao and X H Li and Y Y Xia and Y J Cheng and Y G Xia and P M\"{u}ller-Buschbaum},
url = {\<Go to ISI\>://WOS:001549938900001},
doi = {10.1002/anie.202511336},
year = {2025},
date = {2025-08-14},
journal = {Angewandte Chemie-International Edition},
abstract = {Lithium metal batteries (LMBs) face challenges from unstable and fragile solid electrolyte interphases (SEIs). In this work, we successfully develop a novel electrolyte by effectively modulating the competitive solvation process in LMBs. In this formulation, the C \& horbar;O \& horbar;C motifs of glymes are competitively substituted by other anions and solvents to achieve single oxygen site coordination, thereby facilitating a weak solvation effect. At an apparent concentration of 1.25 M, a solvated sheath enriched with anions and single oxygen-bound complexes is formed, which significantly enhances lithium metal compatibility and promotes rapid desolvation kinetics. The designed electrolyte using weakly solvated structures exhibits remarkable stability at both 25 degrees and 80 degrees C, enabling the lithium iron phosphate (LFP)||Li cell to achieve over 2000 cycles (capacity retention: 90%) and 500 cycles (capacity retention: 96%), respectively. Interestingly, the low N/P ratio LFP||Li (N/P = 1.8) full battery maintains a stable capacity over 50 cycles, and the commercial 1.1 Ah LFP||Li pouch cell shows a great stability (capacity retention: 91.0%, CE: 99.82%) over 20 cycles. The distinctive solvation regulation strategy has paved a novel research avenue for the realization of high-performance LMBs.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Lithium metal batteries (LMBs) face challenges from unstable and fragile solid electrolyte interphases (SEIs). In this work, we successfully develop a novel electrolyte by effectively modulating the competitive solvation process in LMBs. In this formulation, the C & horbar;O & horbar;C motifs of glymes are competitively substituted by other anions and solvents to achieve single oxygen site coordination, thereby facilitating a weak solvation effect. At an apparent concentration of 1.25 M, a solvated sheath enriched with anions and single oxygen-bound complexes is formed, which significantly enhances lithium metal compatibility and promotes rapid desolvation kinetics. The designed electrolyte using weakly solvated structures exhibits remarkable stability at both 25 degrees and 80 degrees C, enabling the lithium iron phosphate (LFP)||Li cell to achieve over 2000 cycles (capacity retention: 90%) and 500 cycles (capacity retention: 96%), respectively. Interestingly, the low N/P ratio LFP||Li (N/P = 1.8) full battery maintains a stable capacity over 50 cycles, and the commercial 1.1 Ah LFP||Li pouch cell shows a great stability (capacity retention: 91.0%, CE: 99.82%) over 20 cycles. The distinctive solvation regulation strategy has paved a novel research avenue for the realization of high-performance LMBs.
1300.
C G Ferreira, C Ros, M Y Zhang, G D Zhou, V Gacha, D Raptis, I D Sharp, J Martorell
In: Acs Energy Letters, 2025, ISSN: 2380-8195.
@article{nokey,
title = {Sub-Bandgap Photon-to-Current Conversion in Bismuth Vanadate Photoanodes and Its Impact on the Maximum Photocurrent Density Achievable for Water Splitting},
author = {C G Ferreira and C Ros and M Y Zhang and G D Zhou and V Gacha and D Raptis and I D Sharp and J Martorell},
url = {\<Go to ISI\>://WOS:001549528700001},
doi = {10.1021/acsenergylett.5c01894},
issn = {2380-8195},
year = {2025},
date = {2025-08-13},
journal = {Acs Energy Letters},
abstract = {The physical properties of bismuth vanadate (BiVO4) make it an appealing semiconductor photoanode for water oxidation in photoelectrochemical cells that aim to produce hydrogen or other solar fuels. However, it has been estimated that its relatively wide bandgap limits achievable photocurrent densities to approximately 7.5 mA/cm2 under 1 sun AM1.5G illumination. Here, we perform high-sensitivity external quantum efficiency measurements and demonstrate that sub-bandgap states within BiVO4 also contribute to photocurrent generation, regardless of the fabrication method or mesoscopic structure. Based on these results and considering Lambertian scattering at the electrolyte/BiVO4 interface, we show that the maximum theoretical current density from BiVO4 can be as high as 12.2 mA/cm2, when assuming complete absorption and conversion of sunlight photons extending to the lowest photon energy for which we experimentally measured photocurrent generation promoted by sub-bandgap states. This finding opens new avenues for design of BiVO4 photoanodes with efficiencies that are much greater than were previously assumed to be possible.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The physical properties of bismuth vanadate (BiVO4) make it an appealing semiconductor photoanode for water oxidation in photoelectrochemical cells that aim to produce hydrogen or other solar fuels. However, it has been estimated that its relatively wide bandgap limits achievable photocurrent densities to approximately 7.5 mA/cm2 under 1 sun AM1.5G illumination. Here, we perform high-sensitivity external quantum efficiency measurements and demonstrate that sub-bandgap states within BiVO4 also contribute to photocurrent generation, regardless of the fabrication method or mesoscopic structure. Based on these results and considering Lambertian scattering at the electrolyte/BiVO4 interface, we show that the maximum theoretical current density from BiVO4 can be as high as 12.2 mA/cm2, when assuming complete absorption and conversion of sunlight photons extending to the lowest photon energy for which we experimentally measured photocurrent generation promoted by sub-bandgap states. This finding opens new avenues for design of BiVO4 photoanodes with efficiencies that are much greater than were previously assumed to be possible.
1299.
G Krach, J Steinadler, R Calaminus, B V Lotsch, W Schnick
Long Used but Hardly Known: Synthesis and Crystal Structure of Tritium Breeding Li2Be2O3 Artikel
In: Chemistry-a European Journal, 2025, ISSN: 0947-6539.
@article{nokey,
title = {Long Used but Hardly Known: Synthesis and Crystal Structure of Tritium Breeding Li2Be2O3},
author = {G Krach and J Steinadler and R Calaminus and B V Lotsch and W Schnick},
url = {\<Go to ISI\>://WOS:001546654300001},
doi = {10.1002/chem.202502209},
issn = {0947-6539},
year = {2025},
date = {2025-08-11},
journal = {Chemistry-a European Journal},
abstract = {A main challenge for the operation of a nuclear fusion reactor is the consumption of tritium during the fusion process and the limited availability of tritium in natural resources or its production in nuclear power plants. The most promising approach is breeding of new tritium within the operating fusion reactor. For this purpose, suitable breeding materials are needed. Lithium beryllium oxides are a promising class of compounds, as they unite both target and neutron multiplier in one material. While there have already been studies on sintered ceramics in the Li2OBeO system, the crystal structure of compounds of a defined composition has so far remained unsolved. Herein, we report on the synthesis of phase-pure Li2Be2O3 in a high-temperature (HT) approach and its structure determination by single-crystal X-ray diffraction (sc-XRD). In addition, the compound was characterized by powder X-ray diffraction (PXRD), solid-state nuclear magnetic resonance (NMR) spectroscopy, and elemental analysis. The thermal stability, which is important for use as blanket material in a fusion reactor, was examined with differential scanning calorimetry (DSC).},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
A main challenge for the operation of a nuclear fusion reactor is the consumption of tritium during the fusion process and the limited availability of tritium in natural resources or its production in nuclear power plants. The most promising approach is breeding of new tritium within the operating fusion reactor. For this purpose, suitable breeding materials are needed. Lithium beryllium oxides are a promising class of compounds, as they unite both target and neutron multiplier in one material. While there have already been studies on sintered ceramics in the Li2OBeO system, the crystal structure of compounds of a defined composition has so far remained unsolved. Herein, we report on the synthesis of phase-pure Li2Be2O3 in a high-temperature (HT) approach and its structure determination by single-crystal X-ray diffraction (sc-XRD). In addition, the compound was characterized by powder X-ray diffraction (PXRD), solid-state nuclear magnetic resonance (NMR) spectroscopy, and elemental analysis. The thermal stability, which is important for use as blanket material in a fusion reactor, was examined with differential scanning calorimetry (DSC).
1298.
E Kolodzeiski, C J Stein
In: Angewandte Chemie-International Edition, 2025.
@article{nokey,
title = {Efficient Electronic-Structure Methods Toward Catalyst Screening: Projection-Based Embedding Theory for CO2 Reduction Reaction Intermediates},
author = {E Kolodzeiski and C J Stein},
url = {\<Go to ISI\>://WOS:001547141000001},
doi = {10.1002/anie.202503418},
year = {2025},
date = {2025-08-07},
journal = {Angewandte Chemie-International Edition},
abstract = {Catalyst screening is a demanding task for computational chemistry since the profound diversity of surface structures under operando conditions is accompanied by high demands on the accuracy to predict the relevant kinetics. Embedding approaches that allow researchers to focus the computational effort on the chemically active regions of interest are promising tools in the pursuit of balancing accuracy and efficiency. However, for metallic catalysts, the required separation of the system into an active part treated with highly accurate methods and an environment is technically hard to achieve due to the delocalization of electrons in the conducting surface. Therefore, studies analyzing the potential of embedding methods for heterogeneous (electro-)catalyst screening are scarce. In this contribution, we demonstrate that simple embedding approaches are indeed achievable for studying metallic catalysts if i) the active orbital space is held consistent over a reaction coordinate and ii) the nonadditive exchange-correlation functional used to calculate the embedding potential includes a fraction of exact exchange to mitigate delocalization errors. We verify the approach for a set of open- and closed-shell CO2 reduction reaction intermediates on different adsorption sites of a Cu(111) surface represented by cluster models to demonstrate that catalyst screening with embedding approaches is achievable.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Catalyst screening is a demanding task for computational chemistry since the profound diversity of surface structures under operando conditions is accompanied by high demands on the accuracy to predict the relevant kinetics. Embedding approaches that allow researchers to focus the computational effort on the chemically active regions of interest are promising tools in the pursuit of balancing accuracy and efficiency. However, for metallic catalysts, the required separation of the system into an active part treated with highly accurate methods and an environment is technically hard to achieve due to the delocalization of electrons in the conducting surface. Therefore, studies analyzing the potential of embedding methods for heterogeneous (electro-)catalyst screening are scarce. In this contribution, we demonstrate that simple embedding approaches are indeed achievable for studying metallic catalysts if i) the active orbital space is held consistent over a reaction coordinate and ii) the nonadditive exchange-correlation functional used to calculate the embedding potential includes a fraction of exact exchange to mitigate delocalization errors. We verify the approach for a set of open- and closed-shell CO2 reduction reaction intermediates on different adsorption sites of a Cu(111) surface represented by cluster models to demonstrate that catalyst screening with embedding approaches is achievable.
1297.
J P Götze, S Petry, S Reiter, H Lokstein, R De Vivie-Riedle
Applying an Anti-Kasha Model Resolves Differences Between Photosynthetic and Artificial Pigments Artikel
In: Journal of Physical Chemistry B, Bd. 129, Nr. 31, S. 7884-7895, 2025, ISSN: 1520-6106.
@article{nokey,
title = {Applying an Anti-Kasha Model Resolves Differences Between Photosynthetic and Artificial Pigments},
author = {J P G\"{o}tze and S Petry and S Reiter and H Lokstein and R De Vivie-Riedle},
url = {\<Go to ISI\>://WOS:001535152400001},
doi = {10.1021/acs.jpcb.5c02465},
issn = {1520-6106},
year = {2025},
date = {2025-08-07},
journal = {Journal of Physical Chemistry B},
volume = {129},
number = {31},
pages = {7884-7895},
abstract = {The current interpretation of excitation energy transfer (EET) processes in natural photosynthesis generally relies on Kasha's rule, suggesting that internal conversion (IC) processes usually outpace any EET between higher excited states. It is, however, known from research on artificial systems that Kasha's rule does not apply to many dyes, especially when found in assembled clusters analogous to photosynthetic chlorophyll (Chl)-protein complexes. In this contribution, a semiempirical Forster-type model is applied to otherwise well-investigated pigments of natural photosynthesis (Chls a, b, c1 and various carotenoids). Strong potential for anti-Kasha processes is identified in all investigated pigments, based on their high Coulomb coupling elements, similar to compounds with already known anti-Kasha properties. The pigments are further found to form strongly delocalized excitons, especially between the higher excited states usually responsible for anti-Kasha pathways. Test calculations with different pigment compositions for various natural light harvesting complexes (LHCII, CP24, CP26, CP29, FCP) demonstrate how the higher band EET network and absorbance could be affected by the presence of accessory pigments: Chl a-only networks should perform anti-Kasha EET, but this is suppressed by the presence of accessory pigments via several mechanisms (exciton disruption, spectral competition, energy sinks and fast, non-Chl a IC). The apparent "special" behavior of photosynthetic systems is thus resolved as the result of pigment mixtures.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The current interpretation of excitation energy transfer (EET) processes in natural photosynthesis generally relies on Kasha's rule, suggesting that internal conversion (IC) processes usually outpace any EET between higher excited states. It is, however, known from research on artificial systems that Kasha's rule does not apply to many dyes, especially when found in assembled clusters analogous to photosynthetic chlorophyll (Chl)-protein complexes. In this contribution, a semiempirical Forster-type model is applied to otherwise well-investigated pigments of natural photosynthesis (Chls a, b, c1 and various carotenoids). Strong potential for anti-Kasha processes is identified in all investigated pigments, based on their high Coulomb coupling elements, similar to compounds with already known anti-Kasha properties. The pigments are further found to form strongly delocalized excitons, especially between the higher excited states usually responsible for anti-Kasha pathways. Test calculations with different pigment compositions for various natural light harvesting complexes (LHCII, CP24, CP26, CP29, FCP) demonstrate how the higher band EET network and absorbance could be affected by the presence of accessory pigments: Chl a-only networks should perform anti-Kasha EET, but this is suppressed by the presence of accessory pigments via several mechanisms (exciton disruption, spectral competition, energy sinks and fast, non-Chl a IC). The apparent "special" behavior of photosynthetic systems is thus resolved as the result of pigment mixtures.
1296.
A Singh, P Bhauriyal, L Quincke, D Blätte, R Guntermann, J L Rupp, T Heine, T Bein
In: Advanced Energy Materials, 2025, ISSN: 1614-6832.
@article{nokey,
title = {Covalent Organic Framework Bipolar Pseudocapacitive Electrodes in an All-Organic Symmetric Lithium-Ion Battery},
author = {A Singh and P Bhauriyal and L Quincke and D Bl\"{a}tte and R Guntermann and J L Rupp and T Heine and T Bein},
url = {\<Go to ISI\>://WOS:001544766400001},
doi = {10.1002/aenm.202501494},
issn = {1614-6832},
year = {2025},
date = {2025-08-06},
journal = {Advanced Energy Materials},
abstract = {Covalent organic frameworks (COFs) have emerged as promising active materials for secondary-ion battery electrodes, owing to their robust porous structure and the flexibility in selecting redox-active building blocks. Here, a novel highly crystalline, electro-active, bipolar-type WTTF-COF, obtained by integrating p-type N,N,N ',N '-tetrakis(4-aminophenyl)-1,4-phenylenediamine (W) and 4,4 ',4 '',4 '''-([2,2'-bi(1,3-dithiolylidene)]-4,4 ',5,5 '-tetrayl)tetrabenzaldehyde (TTF) molecular building blocks via n-type imine linkages, is reported, serving as a Li-ion battery electrode. In Li-ion half cells, WTTF-COF as a cathode features 12-electron dual-ion redox chemistry per unit cell within a stable, unusually wide potential window of 0.1-3.6 V versus Li/Li+, corresponding to a high theoretical capacity of 315 mAh g-1, with an experimental reversible specific capacity of 271 mAh g-1 at 0.1 A g-1. The hybrid redox features coupled with the long-range ordered nanostructure of WTTF-COF enable an efficient pseudo-capacitive charge-storage mechanism. Different diffusion pathways and diffusion coefficients for Li+ and PF6- transport are established through detailed diffusion measurements and theoretical modeling. Among hybrid storage electrodes, WTTF-COF is reported to offer the option to serve as both anode and cathode up to a high rate of 200 mV s-1, as demonstrated in fully organic symmetric cell tests. Summarizing, judiciously designed COFs are suitably established for efficient bipolar electrode applications.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Covalent organic frameworks (COFs) have emerged as promising active materials for secondary-ion battery electrodes, owing to their robust porous structure and the flexibility in selecting redox-active building blocks. Here, a novel highly crystalline, electro-active, bipolar-type WTTF-COF, obtained by integrating p-type N,N,N ',N '-tetrakis(4-aminophenyl)-1,4-phenylenediamine (W) and 4,4 ',4 '',4 '''-([2,2'-bi(1,3-dithiolylidene)]-4,4 ',5,5 '-tetrayl)tetrabenzaldehyde (TTF) molecular building blocks via n-type imine linkages, is reported, serving as a Li-ion battery electrode. In Li-ion half cells, WTTF-COF as a cathode features 12-electron dual-ion redox chemistry per unit cell within a stable, unusually wide potential window of 0.1-3.6 V versus Li/Li+, corresponding to a high theoretical capacity of 315 mAh g-1, with an experimental reversible specific capacity of 271 mAh g-1 at 0.1 A g-1. The hybrid redox features coupled with the long-range ordered nanostructure of WTTF-COF enable an efficient pseudo-capacitive charge-storage mechanism. Different diffusion pathways and diffusion coefficients for Li+ and PF6- transport are established through detailed diffusion measurements and theoretical modeling. Among hybrid storage electrodes, WTTF-COF is reported to offer the option to serve as both anode and cathode up to a high rate of 200 mV s-1, as demonstrated in fully organic symmetric cell tests. Summarizing, judiciously designed COFs are suitably established for efficient bipolar electrode applications.
1295.
L P Kong, P J Williams, F Brushett, J L M Rupp
Unveiling Coexisting Battery-Type and Pseudocapacitive Intercalation Mechanisms in Lithium Titanate Artikel
In: Advanced Energy Materials, 2025, ISSN: 1614-6832.
@article{nokey,
title = {Unveiling Coexisting Battery-Type and Pseudocapacitive Intercalation Mechanisms in Lithium Titanate},
author = {L P Kong and P J Williams and F Brushett and J L M Rupp},
url = {\<Go to ISI\>://WOS:001544773300001},
doi = {10.1002/aenm.202503080},
issn = {1614-6832},
year = {2025},
date = {2025-08-06},
journal = {Advanced Energy Materials},
abstract = {Conventional lithium-ion (Li-ion) batteries and supercapacitors face inherent trade-offs between power and energy densities, restricting their adaptability in applications requiring dynamic performance across both regimes. Here, a "zero-strain" lithium titanate (Li4Ti5O12) as a new class of battery-capacitive material exhibiting dual lithiation mechanisms, combining diffusion-controlled battery-type redox reactions and surface-controlled pseudocapacitive intercalation, depending on the operating potential, is revealed. At approximate to 1.55 V (vs Li/Li+), lithium titanate undergoes a two-phase transition reaction between Li4Ti5O12 and Li7Ti5O12, involving Li migration between 8a and 16c Wyckoff sites. Upon deeper lithiation to potentials near 0 V, Li ions reoccupy the 8a sites, triggering a reversible pseudocapacitive response with fast kinetics. Leveraging these dual lithiation mechanisms, lithium titanate delivers a high reversible capacity of approximate to 215 mAh g-1 at 20 mA g-1, retaining 148 mAh g-1 at 2000 mA g-1. The high-rate capability and cycling stability are attributed to a unique structure with minimal lattice strain during Li-site occupation. This work presents the first clear demonstration of a unique dual-mode charge storage mechanism in lithium titanate, which can reversibly operate in either battery-type or pseudocapacitive regimes.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Conventional lithium-ion (Li-ion) batteries and supercapacitors face inherent trade-offs between power and energy densities, restricting their adaptability in applications requiring dynamic performance across both regimes. Here, a "zero-strain" lithium titanate (Li4Ti5O12) as a new class of battery-capacitive material exhibiting dual lithiation mechanisms, combining diffusion-controlled battery-type redox reactions and surface-controlled pseudocapacitive intercalation, depending on the operating potential, is revealed. At approximate to 1.55 V (vs Li/Li+), lithium titanate undergoes a two-phase transition reaction between Li4Ti5O12 and Li7Ti5O12, involving Li migration between 8a and 16c Wyckoff sites. Upon deeper lithiation to potentials near 0 V, Li ions reoccupy the 8a sites, triggering a reversible pseudocapacitive response with fast kinetics. Leveraging these dual lithiation mechanisms, lithium titanate delivers a high reversible capacity of approximate to 215 mAh g-1 at 20 mA g-1, retaining 148 mAh g-1 at 2000 mA g-1. The high-rate capability and cycling stability are attributed to a unique structure with minimal lattice strain during Li-site occupation. This work presents the first clear demonstration of a unique dual-mode charge storage mechanism in lithium titanate, which can reversibly operate in either battery-type or pseudocapacitive regimes.