Characterization And Photocatalytic Property Of Cu₂S And Doped By Cd Nano-films Prepared By Hydrothermal Method

Photocatalytic oxidation is a new-style wastewater treatment technology for degradation oforganic contaminants, and reveals many advantages, such as: high processing efficiency, simpleprocess equipment, easy operating conditions and so on. Hydrothermal synthesis method has greatpotential for preparing thin film. In this paper, the effects of different sulfur source, the type ofsurfactant, hydrothermal time and hydrothermal temperature on Cu_xS nanostructural film crystalstructures, composition, morphology, film roughness have been studied. Methylene blue dye wasselected as an organic contaminant, the test and mechanism of photocatalytic oxidation has beenstudied under Cu_xS nanostructural thin film as photocatalyst.In the condition of TAA, DETA-2Na as sulfur source and surfactant, the low chalcocite Cu₂Sfilm with smooth surface and uniform particle size can be obtained, and hydrothermal time has littleeffect on the crystal structure and morphology of the film; In photocatalytic process, the addition ofH2O2can effectively inhibit the electron-hole pair recombination, greatly improving thepHotocatalytic activity of the Cu₂S thin film samples. The degradation ratio of the film obtained for1h can reach83.7%for methylene blue solution in80min. With Tu, EDTA-2Na as sulfur source andsurfactant, the obtained Cu₂S nanofilm is Chalcocite-M structure and its photocatalytic efficiency isup to92.8%in80min; With S, EDTA-2Na as sulfur source and as surfactant, the photocatalyticefficiency is only52.8%in80min for the obtained cubic structure Cu7S4nanostructure film.In addition, Cu_xS composite nanofilm has been prepared by doping cadmium acetate. Theexperimental results show that CdS in the composite films is hexagonal crystal structure whenEDTA-2Na as surfactant, and the orthogonal structure of CdS crystals can be obtained with usingSDS as surfactant. In contrast, the CdS crystals with hexagonal structure has the higer photocatalyticefficiency. Doped nanocomposite film can significantly improve photocatalytic speed in a short time.