Preparation of Cr-doped TiO2 Thin Film by Sonochemical/CVD Method and its Visible Light Photocatalytic Activity for Degradation of Paraoxon Pesticide

In this work, nanostructured TiO2 and Cr-doped TiO2 thin films were deposited on glass substrate through sonochemical-chemical vapor deposition method. The resulting thin films were characterized by X-ray diffraction, Scanning Electron Microscopy (SEM), UV-visible absorption spectroscopy, and photoluminescence spectroscopy techniques. The TiO2 thin film has nanocubic morphology and the Cr-doped TiO2 thin film contains nanostructures with irregular shapes in its structures in which these nanostructures themselves are composed of nanorods. Doping the TiO2 by Cr resulted in a decrease in the band gap energy of TiO2 and also in the reduction of photogenerated electron-hole recombination rate. The visible light photocatalytic activity of the prepared thin films was also investigated for degradation of paraoxon pesticide. According to the obtained results, the Cr-doped TiO2 thin film has higher photocatalytic activity than undoped TiO2 thin film. Moreover, reusability test results revealed that the Cr-doped TiO2 thin film has higher stability than undoped TiO2 thin film.