Efficiency of Cu2O/BiVO4 particles prepared with a new soft procedure on the degradation of dyes under visible-light irradiation

Cu2O/BiVO4 composites with different concentrations of Cu2O were synthesized by a simple impregnation method at 200 degrees C under N-2 atmosphere for 4h. The as-synthesized samples were characterized by X-ray powder diffraction, scanning electron microscopy, UV-vis diffuse reflection absorption and vis photoluminescence. The morphology of the as-synthesized composites with different weight ratios of Cu2O is composed by quasi-spherical and dendrite-like particles. The photocatalytic performance of the Cu2O/BiVO4 composites was evaluated by degradation of methyl orange solutions under visible-LED irradiation. The results obtained show that the photocatalytic behavior of the p-n heterojunction Cu2O/BiVO4 composites was better than pure Cu2O and BiVO4. The variation of the reaction parameters, such as solution pH and presence of 02, improved the photocatalytic performance of Cu2O/BiVO4 composite. Meanwhile, a possible mechanism for methyl orange photocatalytic degradation over Cu2O/BiVO4 photocatalysts was proposed. The chemical stability and reusability of Cu2O/BiVO4 powders were also investigated. (C) 2014 Elsevier B.V. All rights reserved.