Photochemical synthesis of copper sulphide/titanium oxide photocatalyst

Copper sulphide powder was obtained by the photochemical synthesis and thin films were developed by doctor blade deposition of CuxS and CuxS/TiO2 composites with photocatalytic properties. The photochemical process could be adjusted to prepare CuxS with different photocatalytic activities by changing the CuSO4:Na2S2O3 molar ratio while keeping other conditions unchanged (solutions pH, solutions volume, irradiation time and intensity). The powder and thin film properties were characterized in terms of: the Fourier transform infra-red (FTIR), the X-ray diffraction (XRD), UV-vis spectroscopy, atomic force microscopy (AFM). The photocatalytic process using CuxS and coupled CuxS/TiO2 thin film semiconductors in the dyes photodegradation (methyl orange and methylene blue) was investigated. The photocatalytic activity of CuxS/TiO2 nanocomposites depends on the CuxS:TiO2 ratio: the best results correspond to the CuxS/TiO2 (CuxS:TiO2 = 3:7) photocatalysts, with high efficiency (almost 99%) after 300 min for methyl orange, respectively after 180 min for methylene blue degradation, under UV irradiation, when H2O2 is added in photocatalytic process. The semiconductors association and the films homogeneity limit the electron-hole recombination, resulting in good efficiency in dyes photodegradation even under visible light irradiation. (C) 2011 Elsevier B.V. All rights reserved.