Low temperature one-pot synthesis of Cu-doped ZnO/Al2O3 composite by a facile rout for rapid methyl orange degradation.

ZnO/Al2O3 composite modified by 2.5-10wt% Cu were prepared using a set of wet chemical techniques (solvothermal, co-precipitation, ultrasonic and reflux) and characterized. All processes were done under the atmospheric condition and without any calcination step. The product was characterized by PXRD, FE-SEM, FT-IR and UV-Vis spectroscopy. The microscopy images clearly showed lamellar particles morphology in nano regime. X-ray diffraction studies revealed the wurtzite-type ZnO and γ-Al2O3 crystallinity. The Band gap varied from 3.20eV for the un-doped Al2O3/ZnO sample to 2.18eV for the Al2O3/ZnO:Cu with Cu content of 10%. Formed Al2O3/ZnO:Cu composite exhibited a supreme photocatalytic performance upon the degradation of methyl orange (MO) under visible-light irradiation. The optimum catalyst indicated completely remove of MO dye with the 15mgL-1 concentration from the water after 50min photocatalytic reaction time, where for the optimum sample the removal efficiency was 77% after only 10min reaction. Results showed that the inserting of Cu in composite improves the photocatalytic activity of ZnO under visible light. The degradation rate of MO for optimum Cu-doped sample was almost 20 times the un-doped sample.