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

ZnO/Cu(2)O compound photocatalysts were prepared by "soak-deoxidize-air oxidation" with different concentrations of Cu(2+) (0.125, 0.25, 0.5, 1, 1.5 and 2 mol/L). The prepared ZnO/Cu(2)O 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 Cu(2+) concentration. Cu(2)O belonged to cubic structure and the crystallinity increased with the increase of Cu(2+) concentration. ZnO were rods and bulks which had diameter of about 300-400 nm, some small round Cu(2)O particles which had a diameter of about 50 nm adhered to these rods and bulks. In the compounds the mole ratio of Cu(2)O 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 Cu(2)O to ZnO increasing. The photocatalytic activities of ZnO/Cu(2)O compound were evaluated using a basic organic dye, methyl orange (MO). It was found that, compared with pure ZnO, the photocatalytic properties of ZnO/Cu(2)O compound were improved greatly and some compounds were better than pure Cu(2)O.