Visible-light-driven photodegradation of Methyl Orange using Cu2O/ZnAl calcined layered double hydroxides as photocatalysts

The Cu2O/ZnAl calcined layered double hydroxides (Cu2O/ZnAl-CLDH) composites had been successfully synthesized by a facile method. The prepared photocatalysts were characterized by X-ray diffraction, Scanning electron microscopy, X-ray photoelectron spectroscopy and UV-vis diffuse reflectance spectra to show the structure of the as-synthesized materials. The results revealed that the Cu2O nanoparticles were evenly distributed on the surface or the internal frame Of ZnAl-CLDH to form the heterostructure of ZnO-Cu2O. The photocatalytic performance of Cu2O/ZnAl-CLDH was evaluated by the photodegradation of Methyl Orange (MO) under visible light irradiation. The effects of the Cu/CLDH molar ratio, calcination temperature and MO concentration were investigated. The photocatalyst shows a high photocatalytic activity (90.18%) at the optimum of Cu/CLDH molar ratio of 1:1, calcination temperature of 500 degrees C and initial MO concentration of 20 mg/L. In addition, after three cycles the removal efficiency of MO is still higher than 80% for reused Cu2O/ZnAl-CLDH, demonstrating its great potential application in the field of photocatalysis. From the experimental results, a possible photocatalytic mechanism of the Cu2O/ZnAl-CLDH composite was proposed. (C) 2016 Elsevier B.V. All rights reserved.