Facile growth of AgVO3 nanoparticles on Mo-doped BiVO4 film for enhanced photoelectrochemical water oxidation

Abstract

BiVO4 is largely restricted by its intrinsic poor electron mobility and sluggish surface reaction. Aiming at eliminating the deficiency of BiVO4, we assemble a novel composite photoanode through simultaneous bulk and surface modification. In detail, controllable Mo doping is manipulated through a spin-coating method, and AgVO3 nanoparticles are loaded by successive ionic layer adsorption and reaction (SILAR) process. The as-prepared photoanode boosts the photocurrent density by 7 folds at 1.23 V vs. RHE and moves the onset potential negatively by 387 mV compared to the bare BiVO4. Furthermore, the charge injection efficiency is substantially boosted to 49% at 1.23 VRHE, nearly 5 times as that of pure BiVO4. With detailed physical and electrochemical characterization, we reveal the essential reason for the boosted photoelectrochemical activity. Appropriate Mo doping can simultaneously enhance the carrier density and electron mobility of BiVO4. Specifically, more (0 4 0) facet are exposed for retarding charge recombination and increasing photocatalytic reaction sites. Then the simple SILAR process grows AgVO3 nanoparticles homogeneously with uniform diameter of 3–5 nm on BiVO4, forming p-n heterojunction to accelerate charge separation, and abundant oxygen vacancy emerged on the surface, which has been demonstrated as active sites for water oxidation reaction.