Preparation of ZnO/g-C3N4 composite photocatalyst and photocatalytic reduction of U(Ⅵ)

Based on ZnO and melamine, the ZnO/g-C3N4 for photocatalytic U(Ⅵ) reduction was pre-pared by thermal polymerization methods. The surface morphology, lattice structure, element composition and photocatalytic efficiency were analyzed by SEM,XRD,XPS, PL and UV-Vis methods.The results show that the doping of ZnO reduces the recombination rate of photogenerated electrons and holes,expands the response range of the material to visible light,makes ZnO/g-C3N4 have higher photocatalytic activity. When pH=5 and dosage is 0.5 g/L, the highest U(Ⅵ) removal rate can reach 97% after dark reaction for 30 min and light reaction for 30 min. The U(Ⅵ) on the surface of the photocatalyst can be reduced to U(Ⅳ). The photoelectron e- is the main factor for reducing U(Ⅵ) to U(Ⅳ).