Prediction the photocatalytic water splitting of bismuth vanady1 oxyhalide BiVO₃F based on density functional theory

BiVO₃F is a promising material used in solar energy conversion systems. Here, we report the calculated structural, electronic, and surface reaction properties using the PBE and hybrid density functionals. We found it is a direct band gap semiconductor, and the calculated band gap is consistent with experimental value only using the hybrid density functional with a fraction of Hartree Fock (HF) exchange α=0.1. The (001) surface is the most stable surface among all the low index (001), (010), (100), (110), (101), (011), and (111) surfaces. There are V and Bi sites exposed on (001) surface which can serves as activity sites. That is quite different from BiVO₄ where only Bi sties can be taken as surface reaction sites. The OER intermediates OH* and OOH* prefer to form a bridge structure on both V and Bi sites. This makes the first proton removal step is very easy, but the O-O bond is difficult to form which leads the overpotential of OER is very high. Our work plays a guide principle to design the high efficiency photocatalysis and photoanodes based on BiVO₃F.