Z-scheme BiVO4/g-C3N4 heterojunction: an efficient, stable and heterogeneous catalyst with highly enhanced photocatalytic activity towards Malachite Green assisted by H2O2 under visible light

BiVO4/g-C3N4 heterojunction was successfully prepared by wet impregnation-calcination method, and as a photoactive material, a new photocatalytic system was formed by cooperating with H2O2. With the illumination of visible light, the degradation efficiency of Malachite Green (MG) could reach 98.3% in 60 min. A variety of conventional characterization techniques, which include XRD, TEM, FT-IR, DRS, PL and so on, have been used to identify micromorphology, crystal structure, physical and chemical properties, and optical properties of BiVO4/g-C3N4 heterojunction. Different factors of photocatalytic efficiency such as the amount of BiVO4 loading on g-C3N4, catalysis doses, the dosing of H2O2, initial concentration and pH of MG solution were explored. Free radical trapping experiments and energy band analysis results indicate that a Z-type electron transfer mechanism is formed in the system, and H2O2 played a significant role on the process of degradation.

Automated summary

A BiVO4/g-C3N4 heterojunction was successfully prepared by wet impregnation-calcination method, forming a new photocatalytic system that can efficiently degrade pollutants with the illumination of visible light. Various techniques were used to identify the properties of the heterojunction, and factors affecting photocatalytic efficiency were explored, indicating the significant role of H2O2 in the degradation process.