Efficient solar-powered water oxidation over BiVO4-based anodes requires coupling photoactive semiconductors to improve inferior activity and stability. Herein, we examine how functionalization with coated tungsten trioxide WO3 affects the photoelectrocatalytic performance of TaON–BiVO4 photoanodes prepared by the doctor-blade method. The effects of the formation of the particularly-porous microstructure and PEC performance of the resulting anodes are explored. Significant enhancements were achieved in water oxidation photocurrent densities at 1.23 V (vs. RHE) with the use of TaON–BiVO4/WO3 photoanodes compared to unmodified TaON–BiVO4. All the composites and photoanodes were studied via numerous characterization methods. Besides, the formation process and probable transfer mechanism of photoinduced carriers were also investigated in detail.
