Preparation of Rare Earth Lu-doped TiO2 Film by Sol-gel Method and Its Photocatalytic Degradation of Methyl Orange Under Natural Light

Abstract

TiO2 can effectively degrade organic pollutants under ultraviolet radiation. Due to the large band gap of TiO2, natural light is not suitable for catalysis, which reduces the applicability of TiO2 materials. To use the natural light source more effectively, the sol-gel preparation process of the rare earth element Lu-doped TiO2 thin film was studied. XRD experiment was used to analyze the crystal characteristics of Lu-doped TiO2 film. The light absorption of Lu-doped TiO2 film was measured by a dual-beam UV-visible spectrophotometer. The degradation effect of Lu-doped TiO2 film on methyl orange under natural light was studied. Compared with the pure TiO2 film, the experimental results indicate that the XRD diffraction peaks begin to shift to the left. The absorption of Lu-doped TiO2 film intensity in the ultraviolet and visible light range is higher. Using the tangent method, the bandgap of Lu-doped TiO2 film is estimated to be about 2.9 eV. Under natural light conditions, the characteristic peak value of the methyl orange solution decreased significantly after 72 h exposure.