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

Abstract

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.