Interface modulation of BiVO4 based photoanode with Bi(III)Bi(V)O4 for enhanced solar water splitting

Abstract Despite being considered as one of the most promising semiconductor photocatalysts, BiVO4 still suffers the problems of inefficient light harvesting, multiple charge recombination channels and back reactions, restricting its application for solar energy conversion. Here, we demonstrate a unique Bi2O4(4 0 0)/BiVO4(0 4 0) heterojunction prepared via an oxidation conversion process, which dramatically accelerated the interfacial charge transfer compared to pure BiVO4. Furthermore, with Mo doping, carbon quantum dots (CQDs) loading and Ni-FeOOH co-catalyst deposition, the resulting Bi2O4/Mo-BiVO4/CQDs/Ni-FeOOH photoanode reaches a remarkable photocurrent density of 6.7 mA/cm2 at 1.23 V vs. RHE under AM 1.5G irradiation in the absence of hole scavengers. Our findings demonstrate that proper material interface engineering together with composition tuning provides a viable route to achieve highly efficient solar water splitting.