Construction of ternary heterostructured Ag/Ag2O@ZnO@g-C3N4 nanocomposite as an widened visible light photocatalyst for the organic oxidation

Abstract

Two dimension g-C3N4 was synthesized by thermal polymerization using mixture urea and melamine. The metal oxide Ag2O and ZnO were loaded to nanolayer of g-C3N4. The composites Ag/Ag2O@ZnO@g-C3N4 were constructed by Ag2O and ZnO which were defined for p-type and n-type semiconductor to form heterojunctions. The samples were characterized by X ray diffraction(XRD), transmission electron microscopy(TEM), X ray photoelectron spectroscopy (XPS) and UV/Vis diffuse reflectance spectroscopy (UV–vis DRS). The experiment results indicate that Ag2O and ZnO were uniformly loaded to nanolayer of g-C3N4 and heterojunction of Ag/Ag2O@ZnO@g-C3N4 was constructed. The photocatalytic activity of Ag/Ag2O@ZnO@g-C3N4 was characterized by degradation of methylene blue (MB) under the widened visible light-driven. The photodegradation efficiency of MB was 64.486%, 87.724%, 91.611%, 96.700% and 99.999% over g-C3N4, ZnO@g-C3N4, Ag/Ag2O@g-C3N4, Ag/Ag2O@ZnO@g-C3N4-1 and Ag/Ag2O@ZnO@g-C3N4-2, respectively. The results show that the photocatalytic activity of Ag/Ag2O@ZnO@g-C3N4 was enhanced based on the p-n structure which decreased the recombination rates of photoinduced electron hole between metal oxide and g-C3N4. Finally, photocatalytic mechanism of Ag/Ag2O@ZnO@g-C3N4 was discussed for ternary heterostructured catalysts.