The preparation of Zn 2+-doped TiO 2 nanoparticles by sol–gel and solid phase reaction methods respectively and their photocatalytic activities

Abstract

The photocatalytic oxidation of the organic pollutants with TiO 2 as photocatalyst has been widely studied in the world, and many achievements have been made. The degradation of pollutants is highly related to the photocatalytic activity of TiO 2. It is demonstrated that doping ions to TiO 2 is one way to enhance the photocatalytic activity of TiO 2. In this paper, Zn 2+-doped TiO 2 nanoparticles were prepared through sol–gel and solid phase reaction methods, characterized by means of X-ray diffraction (XRD) and transmission electron microscopy (TEM). The photocatalytic activity of the elaborated powders was studied following the degradation of Rhodamine B. The results showed that the photocatalytic activity of Zn 2+-doped TiO 2 prepared by sol–gel method is close to that of pure TiO 2 particles, however, the photocatalytic activity of Zn 2+-doped TiO 2 prepared by solid phase reaction method is much higher than that of pure TiO 2 particles. The most efficient degradation of Rhodamine B was found with TiO 2 particles doped with 0.5% Zn 2+ in mole and calcined at 500 °C. Also the reason for the enhancement of the photocatalytic activity of TiO 2 by Zn 2+ doping through solid phase reaction method was discussed.