Abstract
The supported mixed oxide (Rh2-yCryO3)/(Ga1-xZnx)(N1-xOx) photocatalyst, highly active for splitting of H2O, was extensively characterized for its bulk and surface properties with the objective of developing fundamental structure-photoactivity relationships. Raman and UV-vis spectroscopy revealed that the molecular and electronic structures, respectively, of the oxynitride (Ga1-xZnx)(N1-xOx) support are not perturbed by the deposition of the (Rh2-yCryO3) NPs. Photoluminescence (PL) spectroscopy, however, showed that the oxynitride (Ga1-xZnx)(N1-xOx) support is the source of excited electrons/holes and the (Rh2-yCryO3) NPs greatly reduce the undesirable recombination of photoexcited electron/holes by acting as efficient electron traps as well as increase the lifetimes of the excitons. High Resolution-XPS and High Sensitivity-LEIS surface analyses reveal that the surfaces of the (Rh2-yCryO3) NPs consist of Rh3+ and Cr3+ mixed oxide species. In situ AP-XPS help to reveal that the Rh3+ and surface N atoms are involved in water splitting. Dispersed RhOx species on the (Ga1-xZnx)(N1-xOx) support and on CrOx NPs were found to be the photocatalytic active sites for H2 generation and N and Zn sites from the (Ga1-xZnx)(N1-xOx) support are the photocatalytic active site for O2 generation. The current investigation establishes the fundamental structure-photoactivity relationships of these visible light activated photocatalysts.
Original language | English |
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Pages (from-to) | 6650-6658 |
Number of pages | 9 |
Journal | ACS Catalysis |
Volume | 8 |
Issue number | 7 |
DOIs | |
State | Published - Jul 6 2018 |
Bibliographical note
Publisher Copyright:© 2018 American Chemical Society.
Keywords
- AP-XPS
- HS-LEIS
- photocatalysis
- photocatalyst
- spectroscopy
- water splitting