Preparation of ZnO/Cu2O compound photocatalyst and application in treating organic dyes

ZnO/Cu2O compound photocatalysts were prepared by soak-deoxidize-air oxidation with different concentrations of Cu2+ (0.125, 0.25, 0.5, 1, 1.5 and 2 mol/L). The prepared ZnO/Cu2O samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM). energy-dispersive spectrometer (EDS), UV-vis diffuse reflectance spectrometer, and photochemical reaction instrument. The results show that ZnO was hexagonal wurtzite structure and the crystallinity had no change with the increase of Cu2+ concentration. Cu2O belonged to cubic structure and the crystallinity increased with the increase of Cu2+ concentration. ZnO were rods and bulks which had diameter of about 300-400 nm, some small round Cu2O particles which had a diameter of about 50 nm adhered to these rods and bulks. In the compounds the mole ratio of Cu2O to ZnO was 0.017, 0.025, 0.076, 0.137, 0.138, and 0.136, respectively. An absorbance in the visible light region between 400 and 610 nm was seen and the reflection rate became less with the mole ratio of Cu2O to ZnO increasing. The photocatalytic activities of ZnO/Cu2O compound were evaluated using a basic organic dye, methyl orange (MO). It was found that, compared with pure ZnO, the photocatalytic properties of ZnO/Cu2O Compound were improved greatly and some compounds were better than pure Cu2O, (C) 2009 Elsevier B.V. All rights reserved.