Enhancement of visible light photocatalytic activity of BiVO4 by polypyrrole modification

In this study, the different amounts of polypyrrole modified BiVO4 photocatalyst were synthesized by oxidative polymerization of pyrrole. The photocatalytic activity of polypyrrole and vanadate bismuth (PPy/BiVO4) composite was determined by photocatalytic degradation of Rhodamine B (RhB) under visible light irradiation. The results showed that PPy could not only affect the crystal structure and the morphology of BiVO4 photocatalyst, but also had a great influence on the photocatalytic activity of pure BiVO4. It was also found that PPy/BiVO4 with the highest photocatalytic activity when the doping amount of PPy was 5%, and the RhB degradation rate could reach 95.72%. This paper also discussed the possible mechanism of enhanced activity: the photogenerated holes in the valence band of BiVO4 can be directly transferred to the π orbital of PPy. At the same time, photogenerated electrons can be transferred to the conduction band of BiVO4, resulting in charge separation and stabilization, thereby effectively preventing the recombination of photogenerated electrons and holes. •It is the first example of doping PPy to improve BiVO4 photocatalyst, and the RhB degradation rate can reach 95.72%.•The highest photocatalytic activity when the doping amount was 5%, and the RhB degradation rate reached 95.72%.•Photogenerated electrons can be transferred to the conduction band of BiVO4, resulting in charge separation and stabilization, thereby effectively preventing the recombination of photogenerated electrons and holes.