Freeing the surface-bound excitons to facilitate water oxidation catalysis in BiVO4 photoanode

Illuminating the charge transport at photoanode-electrolyte interface is pivotal for optimizing photo-electrochemical (PEC) water oxidation performance of BiVO4. Our study demonstrates a preferentially photogenerated electrons trapping process at BiVO4 surface, followed by the formation of surface-bound excitons. A facile LSV treatment method is described, which remarkably passivate the surface electron trapping states by the formation surface oxygen vacancies. The surface oxygen vacancies could free the photogenerated holes from the surface-bound excitons. As a result, more photogenerated holes are available on BiVO4 surface and the PEC performance is enhanced.

Automated summary

The study demonstrates a preferential electron trapping process and surface-bound exciton formation at the BiVO4 surface, which can be mitigated by a facile LSV treatment to enhance PEC performance.