Construction of BiVO₄/BiOCl@C Z-scheme heterojunction for enhanced photoelectrochemical performance

A Z-scheme heterostructure of Mo, W co-doped BiVO₄ (Mo,W:BVO/BiOCl@C) was fabricated by a simple solid solution drying and calcination (SSDC) method. The heterostructure was characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR), X-ray photoelectron spectroscopy (XPS), etc. Under visible light irradiation, Mo,W:BVO/BiOCl@C heterostructure exhibits excellent photoelectrochemical capability compared with other as-prepared samples. The photocurrent density and the incident photon-to-electron conversion efficiency (IPCE) are about 5.4 and 9.0 times higher than those of pure BiVO₄, respectively. The enhancement of the photoelectrochemical performance can be attributed to the construct of Z-scheme system, which is deduced from the radical trapping experiments. The Mo,W:BVO/BiOCl@C Z-scheme heterojunction enhances the visible-light absorption and reduces the recombination rate of charge carriers. This work provides an effective strategy to construct Z-scheme photoelectrodes for the application of photoelectrochemical water splitting.