Preparation, Characterization and Photocatalytic Activity of Nano -sized Pure and Metal-Doped TiO 2 and ZnO and their Uses in Water treatment

Pure and doped nanoparticles M-ZnO and M / -TiO2 with various metal ions (M=Ag, Cu, Fe, Ti and M / =Zn and Cu) were prepared by both precipitation and sol-gel methods. All samples well characterized by XRD, SEM, FT-IR and UV-vis. spectroscopy techniques. Photo catalytic activities towards a degradation of methyl orange (M.O) and chemical oxygen demand (COD) were studied for the samples investigated. XRD results showed the formation of pure anatase and wurtzite structure for TiO2 and ZnO samples, respectively . The crystallite sizes lie in the range of 9-21 nm for TiO2 and 10-30 nm for ZnO samples. The optical study showed a shif t in the optical absorption edge to longer wavelength with decreasing in the band gap energy of doped-TiO2 and doped-ZnO. The doped-TiO2 and doped-ZnO showed higher photocatalytic activity compared to that of both pure TiO2 and ZnO. COD tests were done for all samples and showed a highest COD value for the Cu doped TiO2.