Visible-light photocatalytic decolorization of Orange II on Cu₂O/ZnO nanocomposites

Cu₂O/ZnO nanocomposites were synthesized by a coprecipitation method and were applied to degrade dye wastewater. The prepared nanocomposites were characterized by X-ray diffraction, scanning electron microscopy, high resolution transmission electron microscopy and UV-vis diffuse reflectance spectra. The effects of initial Orange II (OII) dye concentration, pH and dosage of catalyst amount were investigated in the decomposition of OII dye by the nanocomposites. The best conditions for the dye decomposition by Cu₂O/ZnO nanocomposites were found to be in the neutral solution when the dosage of catalyst was 200 mg/L with an OII concentration of 50 mg/L at room temperature. Under the above conditions, nearly 80% decolorization efficiency of OII was achieved by Cu₂O/ZnO nanocomposites within 2 h of reaction time and this efficiency was much higher than that of either pure Cu₂O or ZnO.