Synthesis and High Photocatalytic Activity of Zn-doped TiO2 Nanoparticles by Sol-gel and Ammonia-Evaporation Method

Photocatalysis has been applied to decompose the waste and toxic materials produced in daily life and in the global environment. Pure TiO2 (Zn-TiO2-0) and Zn-doped TiO2 (Zn-TiO2-x, x = 3-10 mol %) samples were synthesized using a novel sol-gel and ammonia-evaporation method. The Zn-doped TiO2 samples showed high photocatalytic activity for the degradation of methylene blue (MB). The physicochemical properties of the samples were investigated using XRD, SEM, ICP, DLS and BET methods. In addition, the most important measurement of photocatalytic ability was investigated by a UV-vis spectrophotometer. The effects of the mol % of zinc ion doping in TiO2 on photocatalytic activity were studied. Among the mol % Zn ions investigated, the Zn-TiO2-9 sample showed the highest photoreactivity. This sample removed 91.4% of the MB after 4 h, while the pure TiO2 only removed 46.4% of the MB.