A novel Ti-doped BiVO4 photoanode with NiFeOx cocatalyst for fast charge transfer towards enhanced photoelectrochemical water oxidation

Bismuth vanadate (BiVO4), a widely utilized photoanode material, encounters limitations in its application due to sluggish water oxidation kinetics. In this study, a titanium-doped, NiFeOx-modified BiVO4 photoanode (Ti–BiVO4/NiFeOx) was developed using electrodeposition and solution immersion method. As-prepared photoanode demonstrates significantly enhanced photocurrent density, achieving 5.4 mA cm-2 at 1.23 VRHE, which is threefold than that of the pristine BiVO4 photoanode. Additionally, it exhibits excellent long-term photo stability. The incorporation of titanium can modulate the bandgap of BiVO4, and the co-catalytic modification with NiFeOx can promote surface charge transfer, thereby enhancing the water oxidation kinetics. The Mott-Schottky analysis reveals a higher carrier density for Ti–BiVO4/NiFeOx. Computational findings further illustrate that the Ti–BiVO4/NiFeOx photoanode boasts an 86.58% surface charge transfer efficiency at 1.23 VRHE, substantially surpassing the unmodified BiVO4 photoanode (43.63%). Consequently, the combined strategies of bandgap control and interface engineering effectively enhance the photoelectrochemical performance of BiVO4 photoanodes, presenting a promising pathway for water splitting applications.