Leveraging electron spin driven photocatalytic hydrogen evolution ability of BiVO4 via crystal facet engineering and iron ion infiltration strategies

An electron spin regulated hydrogen evolution reaction (HER) for photocatalyst is significant to understand the underlying photocatalytic mechanism. Here, the iron with gradient distribution in BiVO4 can successfully activate HER of Fe-BiVO4. Mechanical performance calculations indicate that doped Fe3+ replacing V site can form stable chemical structure for BiVO4. Theoretical calculations suggest that the photo-generated electrons migrate from bulk to defect sites in surface layers of Fe-BiVO4. The doped Fe ions effectively improves the carrier transport ability and significantly reduces the carrier recombination probability. Electron spin state change of the 1Fe-BiVO4 (Mag) enhances evidently the current density in photocatalysis, and increases markedly the HER performance compared with that of 1Fe-BiVO4. More importantly, the magnetization further prolongs carrier lifetime and optimizes rate determining step free energy of water dissociation for Fe-BiVO4. Our work opens a new way to understand the effect of magnetic field controlling spin states on photocatalytic HER.