Preparation and Characterization of p-n Heterojunction Photocatalyst Cu2O / In2O3 and its Photocatalytic Activity under Visible and UV Light Irradiation

Abstract

The photocatalyst was prepared from indium hydroxide calcined at for 3 h. The p-n heterojunction photocatalyst was prepared by ballmilling through doping into and using absolute alcohol as a disperser. The photocatalyst was characterized by X-ray powder diffraction, UV-visible diffuse reflectance spectroscopy, X-ray photoelectron spectroscopy, terephthalic acid photoluminescence probing technique, photoluminescence emission spectra, and transmission electron microscopy. The results showed that the photocatalytic activity of the was much higher than that of on the photocatalytic reduction of . However, the photocatalytic activity was much lower than that of on the photocatalytic oxidation of methylene blue. Namely, has higher photocatalytic reduction activity but lower photocatalytic oxidation activity. For the photocatalytic reduction of , the optimum amount of doped is 0.5 wt %. Compared with pure , the photoabsorption wavelength range of the photocatalyst redshifts and improves the utilization of the total spectrum. The effect of ballmilling time on the photocatalytic activity was investigated. The mechanisms of influence on the photocatalytic activity were also discussed by the p-n junction principle and the valance band theory.