2024
Kumar, Abhijeet M.; Yagodkin, Denis; Rosati, Roberto; Bock, Douglas J.; Schattauer, Christoph; Tobisch, Sarah; Hagel, Joakim; Höfer, Bianca; Kirchhof, Jan N.; López, Pablo Hernández; Burfeindt, Kenneth; Heeg, Sebastian; Gahl, Cornelius; Libisch, Florian; Malic, Ermin; Bolotin, Kirill I.
Strain fingerprinting of exciton valley character in 2D semiconductors Journal Article
In: Nat Commun, vol. 15, no. 1, 2024, ISSN: 2041-1723.
@article{Kumar2024,
title = {Strain fingerprinting of exciton valley character in 2D semiconductors},
author = {Abhijeet M. Kumar and Denis Yagodkin and Roberto Rosati and Douglas J. Bock and Christoph Schattauer and Sarah Tobisch and Joakim Hagel and Bianca Höfer and Jan N. Kirchhof and Pablo Hernández López and Kenneth Burfeindt and Sebastian Heeg and Cornelius Gahl and Florian Libisch and Ermin Malic and Kirill I. Bolotin},
doi = {10.1038/s41467-024-51195-y},
issn = {2041-1723},
year = {2024},
date = {2024-12-00},
journal = {Nat Commun},
volume = {15},
number = {1},
publisher = {Springer Science and Business Media LLC},
abstract = {AbstractIntervalley excitons with electron and hole wavefunctions residing in different valleys determine the long-range transport and dynamics observed in many semiconductors. However, these excitons with vanishing oscillator strength do not directly couple to light and, hence, remain largely unstudied. Here, we develop a simple nanomechanical technique to control the energy hierarchy of valleys via their contrasting response to mechanical strain. We use our technique to discover previously inaccessible intervalley excitons associated with K, Γ, or Q valleys in prototypical 2D semiconductors WSe2 and WS2. We also demonstrate a new brightening mechanism, rendering an otherwise “dark” intervalley exciton visible via strain-controlled hybridization with an intravalley exciton. Moreover, we classify various localized excitons from their distinct strain response and achieve large tuning of their energy. Overall, our valley engineering approach establishes a new way to identify intervalley excitons and control their interactions in a diverse class of 2D systems.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
AbstractIntervalley excitons with electron and hole wavefunctions residing in different valleys determine the long-range transport and dynamics observed in many semiconductors. However, these excitons with vanishing oscillator strength do not directly couple to light and, hence, remain largely unstudied. Here, we develop a simple nanomechanical technique to control the energy hierarchy of valleys via their contrasting response to mechanical strain. We use our technique to discover previously inaccessible intervalley excitons associated with K, Γ, or Q valleys in prototypical 2D semiconductors WSe2 and WS2. We also demonstrate a new brightening mechanism, rendering an otherwise “dark” intervalley exciton visible via strain-controlled hybridization with an intravalley exciton. Moreover, we classify various localized excitons from their distinct strain response and achieve large tuning of their energy. Overall, our valley engineering approach establishes a new way to identify intervalley excitons and control their interactions in a diverse class of 2D systems.
Mondal, Soumyadip; Nguyen, Huyen T. K.; Hauschild, Robert; Freunberger, Stefan
Individual Marcus-type kinetics controls singlet and triplet oxygen evolution from superoxide Unpublished
2024.
@unpublished{Mondal2024,
title = {Individual Marcus-type kinetics controls singlet and triplet oxygen evolution from superoxide},
author = {Soumyadip Mondal and Huyen T.K. Nguyen and Robert Hauschild and Stefan Freunberger},
url = {https://chemrxiv.org/engage/chemrxiv/article-details/66cdf17720ac769e5f047b68},
doi = {10.26434/chemrxiv-2024-3vrzz},
year = {2024},
date = {2024-08-28},
publisher = {American Chemical Society (ACS)},
abstract = {Oxygen evolution from superoxide is a critical aspect of oxygen redox chemistry. However, the factors determining the formation of often harmful singlet oxygen are unclear. Here, we report that the release of triplet or singlet oxygen is governed by individual Marcus normal and inverted region behavior. Using a wide range of chemical oxidants, we found that as the driving force increases, the initially dominant evolution of triplet oxygen slows down, and singlet oxygen evolution becomes predominant with higher maximum kinetics. This behavior also applies to superoxide disproportionation, the oxidation of one superoxide by another, in both non-aqueous and aqueous systems, where Lewis and Brønsted acidity control driving forces. Our findings suggest ways to understand and control spin states and kinetics in oxygen redox chemistry.},
keywords = {},
pubstate = {published},
tppubtype = {unpublished}
}
Oxygen evolution from superoxide is a critical aspect of oxygen redox chemistry. However, the factors determining the formation of often harmful singlet oxygen are unclear. Here, we report that the release of triplet or singlet oxygen is governed by individual Marcus normal and inverted region behavior. Using a wide range of chemical oxidants, we found that as the driving force increases, the initially dominant evolution of triplet oxygen slows down, and singlet oxygen evolution becomes predominant with higher maximum kinetics. This behavior also applies to superoxide disproportionation, the oxidation of one superoxide by another, in both non-aqueous and aqueous systems, where Lewis and Brønsted acidity control driving forces. Our findings suggest ways to understand and control spin states and kinetics in oxygen redox chemistry.
Batool, Samar; Schubert, Jasmin S.; Ayala, Pablo; Saito, Hikaru; Sampaio, Maria J.; Silva, Eliana S. Da; Silva, Cláudia G.; Faria, Joaquim L.; Eder, Dominik; Cherevan, Alexey
A thiomolybdate cluster for visible-light-driven hydrogen evolution: comparison of homogeneous and heterogeneous approaches Journal Article
In: Sustainable Energy Fuels, vol. 8, no. 6, pp. 1225–1235, 2024, ISSN: 2398-4902.
@article{Batool2024,
title = {A thiomolybdate cluster for visible-light-driven hydrogen evolution: comparison of homogeneous and heterogeneous approaches},
author = {Samar Batool and Jasmin S. Schubert and Pablo Ayala and Hikaru Saito and Maria J. Sampaio and Eliana S. Da Silva and Cláudia G. Silva and Joaquim L. Faria and Dominik Eder and Alexey Cherevan},
doi = {10.1039/d3se01658g},
issn = {2398-4902},
year = {2024},
date = {2024-03-12},
journal = {Sustainable Energy Fuels},
volume = {8},
number = {6},
pages = {1225--1235},
publisher = {Royal Society of Chemistry (RSC)},
abstract = {This study investigates the hydrogen evolution reaction (HER) efficiency of two photosystems incorporating an all-inorganic molecular thiomolybdate [Mo3S13]2− cluster as a HER catalyst.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
This study investigates the hydrogen evolution reaction (HER) efficiency of two photosystems incorporating an all-inorganic molecular thiomolybdate [Mo3S13]2− cluster as a HER catalyst.
Batool, Samar; Langer, Marcel; Myakala, Stephen Nagaraju; Heiland, Magdalena; Eder, Dominik; Streb, Carsten; Cherevan, Alexey
Thiomolybdate Clusters: From Homogeneous Catalysis to Heterogenization and Active Sites Journal Article
In: Advanced Materials, vol. 36, no. 7, 2024, ISSN: 1521-4095.
@article{Batool2023,
title = {Thiomolybdate Clusters: From Homogeneous Catalysis to Heterogenization and Active Sites},
author = {Samar Batool and Marcel Langer and Stephen Nagaraju Myakala and Magdalena Heiland and Dominik Eder and Carsten Streb and Alexey Cherevan},
doi = {10.1002/adma.202305730},
issn = {1521-4095},
year = {2024},
date = {2024-02-00},
journal = {Advanced Materials},
volume = {36},
number = {7},
publisher = {Wiley},
abstract = {AbstractThiomolybdates are molecular molybdenum‐sulfide clusters formed from Mo centers and sulfur‐based ligands. For decades, they have attracted the interest of synthetic chemists due to their unique structures and their relevance in biological systems, e.g., as reactive sites in enzymes. More recently, thiomolybdates are explored from the catalytic point of view and applied as homogeneous and molecular mimics of heterogeneous molybdenum sulfide catalysts. This review summarizes prominent examples of thiomolybdate‐based electro‐ and photocatalysis and provides a comprehensive analysis of their reactivities under homogeneous and heterogenized conditions. Active sites of thiomolybdates relevant for the hydrogen evolution reaction are examined, aiming to shed light on the link between cluster structure and performance. The shift from solution‐phase to surface‐supported thiomolybdates is discussed with a focus on applications in electrocatalysis and photocatalysis. The outlook highlights current trends and emerging areas of thiomolybdate research, ending with a summary of challenges and key takeaway messages based on the state‐of‐the‐art research.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
AbstractThiomolybdates are molecular molybdenum‐sulfide clusters formed from Mo centers and sulfur‐based ligands. For decades, they have attracted the interest of synthetic chemists due to their unique structures and their relevance in biological systems, e.g., as reactive sites in enzymes. More recently, thiomolybdates are explored from the catalytic point of view and applied as homogeneous and molecular mimics of heterogeneous molybdenum sulfide catalysts. This review summarizes prominent examples of thiomolybdate‐based electro‐ and photocatalysis and provides a comprehensive analysis of their reactivities under homogeneous and heterogenized conditions. Active sites of thiomolybdates relevant for the hydrogen evolution reaction are examined, aiming to shed light on the link between cluster structure and performance. The shift from solution‐phase to surface‐supported thiomolybdates is discussed with a focus on applications in electrocatalysis and photocatalysis. The outlook highlights current trends and emerging areas of thiomolybdate research, ending with a summary of challenges and key takeaway messages based on the state‐of‐the‐art research.
Winkler, Daniel; Leitner, Matthias; Auer, Andrea; Kunze-Liebhäuser, Julia
The Relevance of the Interfacial Water Reactivity for Electrochemical CO Reduction on Copper Single Crystals Journal Article
In: ACS Catal., vol. 14, no. 2, pp. 1098–1106, 2024, ISSN: 2155-5435.
@article{Winkler2024,
title = {The Relevance of the Interfacial Water Reactivity for Electrochemical CO Reduction on Copper Single Crystals},
author = {Daniel Winkler and Matthias Leitner and Andrea Auer and Julia Kunze-Liebhäuser},
doi = {10.1021/acscatal.3c02700},
issn = {2155-5435},
year = {2024},
date = {2024-01-19},
journal = {ACS Catal.},
volume = {14},
number = {2},
pages = {1098--1106},
publisher = {American Chemical Society (ACS)},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
