Photocatalytic activity of Cu2O/ZnO nanocomposite for the decomposition of methyl orange under visible light irradiation.

ZnO is modified by Cu₂O by the process of precipitation and calcination. X-ray diffraction has shown that Cu₂O/ZnO catalysts are made of highly purified cubic Cu₂O and hexagonal ZnO. Scanning electron microscopy and transmission electron microscopy have shown that ZnO adhered to the surface of Cu₂O. Due to the doping of Cu₂O, the absorption range of the Cu₂O/ZnO catalyst is shifted from the ultraviolet to the visible region due to diffuse reflection. X-ray photoelectron spectroscopy and photoluminescence spectra have confirmed that there is a substantial interaction between the two phases of the resultant catalyst. The degradation efficiency of Cu₂O/ZnO on methyl orange solution is obviously enhanced compared to Cu₂O and ZnO. The maximum degradation efficiency is 98%. The degradation efficiency is affected by the pH of the solution and initial concentration. After three rounds of recycling, the degradation rate is almost same. This shows a consistent performance of Cu₂O/ZnO. The increase in catalytic ability is related to the lattice interaction caused by the doping of Cu₂O. [ABSTRACT FROM AUTHOR]