Enhanced photocatalytic and photoelectrochemical performance of g-C3N4/BiVO4 heterojunction: A combined experimental and theoretical study

Semiconductor-based photocatalytic technology is regarded as a promising strategy for solve environmental and energy problems. Here, g-C3N4/BiVO4 heterojunction photocatalysts were prepared by a modified sol-gel technique by varying the weight ratio of g-C3N4 under facile conditions. The incorporation of g-C3N4 is found to significantly improve the photocatalytic and photoelectrochemical activity of BiVO4. The optimized g-C3N4/BiVO4 sample exhibits a greatly improved kinetic constant in photocatalytic degradation that is 7.7 times of that in pure BiVO4, and an enhancement of 3 time for the photocurrent density. Systematic experimental studies, combined with first-principles calculations, reveal that the improved photocatalytic and photoelectrochemical activities arise from the efficient separation of charge carriers due to the heterojunctions formed between g-C3N4 and BiVO4. Our work provides a feasible route to develop a high-efficiency photocatalytic technology for environmental contaminants degradation and renewable energy.