TY  - EJOUR
AU  - Derelli, Davide
AU  - Caddeo, Francesco
AU  - Frank, Kilian
AU  - Krötzsch, Kilian
AU  - Ewerhardt, Patrick
AU  - Krüger, Marco
AU  - Medicus, Sophie
AU  - Klemeyer, Lars
AU  - Skiba, Marvin
AU  - Gutowski, Olof
AU  - Dippel, Ann-Christin
AU  - Parak, Wolfgang J.
AU  - Nickel, Bert
AU  - Koziej, Dorota
TI  - Operando X-ray scattering elucidates the photocorrosion mechanism of CuBi<sub>2</sub>O<sub>4</sub> films
M1  - PUBDB-2023-05955
PY  - 2023
AB  - CuBi2O4 has recently emerged as a promising photocathode for photo-electrochemical (PEC) water splitting. However, its fast degradation under operation currently poses a limit to its application. Here, we report a novel method to study operando the semiconductor-electrolyte interface during PEC operation by surface-sensitive high-energy X-ray scattering. We find that a fast decrease in the generated photocurrents correlates directly with the formation of a metallic Bi phase. We further show that the slower formation of metallic Cu, as well as the dissolution of the electrode in contact with the electrolyte, further affect the CuBi<sub>2</sub>O<sub>4</sub> activity and morphology. Our study provides a comprehensive picture of the degradation mechanisms affecting CuBi<sub>2</sub>O<sub>4</sub> electrodes under operation and poses the methodological basis to investigate the photocorrosion processes affecting a wide range of PEC materials. 
LB  - PUB:(DE-HGF)25
DO  - DOI:10.26434/chemrxiv-2023-j1q9w
UR  - https://bib-pubdb1.desy.de/record/594778
ER  -