Transition metal coated TiO2 nanoparticles: Synthesis, characterization and their photocatalytic activity

Transition metal ions (M-TiO2, where M = Cu(II), Ni(II), Co(II) and Fe(III)) loaded TiO2 catalyst were successfully prepared by solid-state dispersion method. The catalysts were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FT-IR), diffuse reflectance spectroscopy (DRS), transmission electron microscopy (TEM), Brunauer-Emmett-Teller (BET). Photocatalytic activities of bare and CuO, NiO, Co3O4, Fe2O3 loaded TiO2 catalysts were compared and the rate constant values were determined from the kinetic studies of the degradation of phenol. The extent of degradation of phenol and its mineralization were confirmed further by HPLC and TOC analyses. The 0.1CuO wt% TiO2 showed the highest percentage of phenol degradation (100%) and highest reaction rate (0.99 mg l(-1) min(-1)) in 90 min. It was also found that the catalytic activity of 0.1CuO-TiO2 was found to be higher than nano TiO2 and P-25 photocatalyst. The profound effect of transition metal oxide catalyst for phenol degradation is generally considered due to the high surface area, small particle size, and high dispersion of CuO, and the presence of more surface OH groups than that of the pure TiO2 photocatalyst. (C) 2013 Elsevier B.V. All rights reserved.