Preparation and Characterization of Rutile-Type TiO2 Doped with Cu

Abstract

Visible-light active photocatalysts were prepared by doping Cu-TiO2 through the sol-gel method. The influence of the preparation conditions such as pH of sol-gel solution and calcination temperature on the properties of TiO2-Cu was investigated. The presence of Cu caused reduction of band-gap energy, which was more visible in the rutile-type TiO2. Low pH of sol-gel solution such as pH 1.5 favorized formation of rutile during calcination and caused slower growth of the crystallites with increasing temperature of calcination in comparison with sol-gel prepared at pH 3. XPS measurements showed that Cu was placed mostly on the surface of TiO2. For sample calcined at 600 °C, the surface concentration of copper was 1.1 wt.%. The presence of both, rutile phase and Cu, increased adsorption of phenol and facilitated its photocatalytic decomposition. Moreover, reduced band-gap energy in rutile-type TiO2-Cu photocatalyst enabled phenol decomposition under visible light.