Z‑Scheme Transfer\nPath of Charges in the BiVO<sub>4</sub>/Bi:ZnIn<sub>2</sub>S<sub>4</sub>‑Co Photoanode for\nPhotoelectrochemical Water Splitting

The significant carrier recombination occurring in the\nbulk of\nBiVO<sub>4</sub> is a primary factor limiting the enhancement of its\nphotoelectrochemical performance. To address this issue, we have incorporated\ntwo-dimensional (2D) nanosheet morphology Bi:ZnIn<sub>2</sub>S<sub>4</sub> and Co sites onto the surface of BiVO<sub>4</sub> to create\nan effective composite photoanode. According to the ultraviolet-visible\ndiffuse reflectance spectroscopy and ultraviolet photoelectron spectroscopy\nresults, it was inferred that a Z-scheme transfer path of charges\nwas formed between BiVO<sub>4</sub> and Bi:ZnIn<sub>2</sub>S<sub>4</sub>, which promoted the separation of bulk phase carriers. Additionally,\nthe 2D topography of Bi:ZnIn<sub>2</sub>S<sub>4</sub> also shortens\nthe transmission distance of the carriers. Furthermore, the presence\nof Co sites provides more active sites for the surface hydrolysis\nreaction to proceed. Ultimately, under AM1.5G illumination, the photocurrent\ndensity of the BiVO<sub>4</sub>/Bi:ZnIn<sub>2</sub>S<sub>4</sub>-Co\nphotoanode reaches 3.6 mA cm<sup>–2</sup> at 1.23 V vs reversible\nhydrogen electrodes.