Boosting the Photoelectrochemical Performance of BiVO₄ Photoanodes by Modulating Bulk and Interfacial Charge Transfer

BiVO4 is an attractive candidate that is used as a photoanode for solar water splitting. Unfortunately, its photoelectrochemical (PEC) performance is restricted by the slow charge transfer ability in the bulk and the interface. In this study, we accelerated bulk charge transfer via introducing oxygen vacancies by Ar plasma treatment and facilitated interfacial carrier transfer by loading a WCoFe oxyhydroxide electrocatalyst. A larger enhancement was achieved compared to the improvement results from the individual modification, and a photocurrent of 5.49 mA/cm2 was obtained under light irradiation in a potassium phosphate (KPi) buffer solution. The results demonstrate that the PEC performance of the BiVO4-based film photoanode is enhanced by integrating synergy effects of favorable factors by introducing oxygen vacancies and loading electrocatalysts.