Preparation, characterization and activity evaluation of p-n junction photocatalyst p-CaFe2O4/n-Ag3VO4 under visible light irradiation.

p-n junction photocatalyst p-CaFe(2)O(4)/n-Ag(3)VO(4) was prepared by ball milling Ag(3)VO(4) in H(2)O doped with p-type CaFe(2)O(4). The structural and optical properties of the photocatalyst were characterized by X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and UV-vis diffuse reflection spectrum (DRS). The photocatalytic activity was evaluated by photocatalytic degradation of methylene blue (MB) under visible light irradiation. The results showed that the photocatalytic activity of the p-CaFe(2)O(4)/n-Ag(3)VO(4) was higher than that of Ag(3)VO(4). When the amount of doped p-CaFe(2)O(4) was 2.0 wt.% and the p-CaFe(2)O(4)/n-Ag(3)VO(4) was ball milled for 12h, the photocatalytic degradation efficiency was 85.4%. Effect of ball milling time on the photocatalytic activity of the photocatalyst was also investigated. The mechanisms of the increase in the photocatalytic activity were discussed by the p-n junction principle.