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.