Studies on Characterization and Photocatalytic Activities of Visible Light Sensitive TiO2 Nano Catalysts Co-doped with Magnesium and Copper

TiO2 (anatase) – based photocatalyst powders containing up to 1.00 wt% of magnesium(II) and copper(II) were synthesized using sol– gel method. The powders were characterized by UV–visible Diffuse Reflectance Spectroscopy (DRS), X-ray diffraction (XRD), N2 adsorption–desorption (BET), X-ray Photoelectron Spectroscopy (XPS), Scanning Electron Microscopy (SEM) and Energy Dispersive Spectrometry (EDS). The XRD patterns show that the undoped TiO2 and co-doped TiO2 have only anatase form, while the BET surface areas of the co-doped TiO2 has larger surface area compared to undoped TiO2. The DRS results indicated that the band gap of co-doped photocatalysts is smaller than undoped TiO2 and there is a shift in absorption band towards visible light. The SEM images of the co-doped catalysts show the smaller particle size than the undoped catalysts. The photocatalytic efficiency of synthesized catalysts was evaluated by the degradation of methylene blue in solution under visible light irradiation. The degradation results revealed that the co-doped catalysts have better photocatalytic activity than undoped TiO2 and Degussa P25.