Nanoplate structured BiVO4 homojunction photoanode for boosting photoelectrochemical water splitting

Abstract

Modulation of two-dimensional (2D) morphology structure is an effective strategy to improve the electron transport properties of BiVO4 photoanodes. However, up to now, the application of 2D BiVO4 in photoelectrochemical water splitting has been extremely scarce reported. Here, a simple method to prepare nanoplate BiVO4 photoanodes is reported. Mo-BiVO4 nanoplates were grafted on the conventional BiVO4 particles by the mild method. Due to the special structure, the specific surface area of the photoanode is increased, which enhances the light absorption and utilization efficiency. Moreover, the homojunction formed between BiVO4 substrate and Mo-doped BiVO4 nanoplate promotes the separation of photogenerated carriers and the transfer of photogenerated holes to the electrolyte interface. The abundant specific surface area also provides more support for the co-catalyst. As a result, under multiple facilitation, the photocurrent density of the BiVO4/Mo-BiVO4/CoPi photoanode is enhanced to 5.1 mA/cm2 at 1.23 V vs. RHE.