English
 
Privacy Policy Disclaimer
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT
Add to Basket
  Local TagsRelease HistoryDetailsSummary

Released
Journal Article

Anionic Disorder and Its Impact on the Surface Electronic Structure of Oxynitride Photoactive Semiconductors

Authors

Hartl,  Anna
External Organizations;

Minár,  Ján
External Organizations;

Constantinou,  Procopios
External Organizations;

/persons/resource/roddatis

Roddatis,  Vladimir
3.5 Interface Geochemistry, 3.0 Geochemistry, Departments, GFZ Publication Database, Deutsches GeoForschungsZentrum;

Alarab,  Fatima
External Organizations;

Müller,  Arnold M.
External Organizations;

Vockenhuber,  Christof
External Organizations;

Schmitt,  Thorsten
External Organizations;

Pergolesi,  Daniele
External Organizations;

Lippert,  Thomas
External Organizations;

Strocov,  Vladimir N.
External Organizations;

Shepelin,  Nick A.
External Organizations;

External Ressource
No external resources are shared
Fulltext (public)

5029630.pdf
(Publisher version), 5MB

Supplementary Material (public)
There is no public supplementary material available
Citation

Hartl, A., Minár, J., Constantinou, P., Roddatis, V., Alarab, F., Müller, A. M., Vockenhuber, C., Schmitt, T., Pergolesi, D., Lippert, T., Strocov, V. N., Shepelin, N. A. (2024): Anionic Disorder and Its Impact on the Surface Electronic Structure of Oxynitride Photoactive Semiconductors. - Chemistry of Materials, 36, 23, 11393-11403.
https://doi.org/10.1021/acs.chemmater.4c01832


Cite as: https://gfzpublic.gfz-potsdam.de/pubman/item/item_5029630
Abstract
The conversion of solar energy into chemical energy, stored in the form of hydrogen, bears enormous potential as a sustainable fuel for powering emerging technologies. Photoactive oxynitrides are promising materials for splitting water into molecular oxygen and hydrogen. However, one of the issues limiting widespread commercial use of oxynitrides is degradation during operation. While recent studies have shown the loss of nitrogen, its relation to reduced efficiency has not been directly and systematically addressed with experiments. In this study, we demonstrate the impact of the anionic stoichiometry of BaTaOxNy on its electronic structure and functional properties. Through experimental ion scattering, electron microscopy, and photoelectron spectroscopy investigations, we determine the anionic composition ranging from the bulk toward the surface of BaTaOxNy thin films. This further serves as input for band structure computations modeling the substitutional disorder of the anion sites. Combining our experimental and computational approaches, we reveal the depth-dependent elemental composition of oxynitride films, resulting in downward band bending and the loss of semiconducting character toward the surface. Extending beyond idealized systems, we demonstrate the relation between the electronic properties of real oxynitride photoanodes and their performance, providing guidelines for engineering highly efficient photoelectrodes and photocatalysts for clean hydrogen production.