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

Abstract Illuminating the charge transport at photoanode-electrolyte interface is pivotal for optimizing photoelectrochemical (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 changes the surface termination of BiVO4 photoanode. The surface electron trapping states could be passivated by LSV treatment and “free” the photogenerated holes from the surface-bound excitons. As a result, more photogenerated holes transfer to BiVO4 surface and the PEC performance is enhanced.