Facile sonochemical-assisted synthesis of Cu/ZnO/Al₂O₃ nanocomposites under vacuum: Optical and photocatalytic studies

This paper reports on the synthesis of Cu/ZnO/Al₂O₃ nanocomposites via a facile sonochemical-assisted approach using new starting reactants. This study was conducted to synthesis and photocatalytic evaluation of the Cu/ZnO/Al₂O₃ nanocomposite in vacuum conditions. The XRD results showed that Cu/ZnO/Al₂O₃ and CuO/ZnO/Al₂O₃ nanocomposites could be obtained after annealing at 600 °C for 3 h in vacuum conditions and in the air, respectively. The effects of Cu:Zn:Al ratio, ultrasonic irradiation, power, time, and capping agent on the product composition and morphology were also studied. Finally, the efficiency of various as-synthesized Cu/ZnO/Al₂O₃ nanocomposites for decolorization of methylene blue were evaluated. According to the results, using ultrasonic irradiation and annealing under vacuum, the efficiency is improved up to 100%. Because in this situation Cu/Cu₂O/ZnO/Al₂O₃ is formed, which has a better absorption (due to Cu₂O) and conductivity (due to Cu) than CuO/ZnO/Al₂O₃ for the photocatalysis process.