Preparation of Titanium Dioxide Thin Films by Atomic Layer Deposition and Its Photocatalytic Activity

TiO2 thin films were prepared by atomic layer deposition on K9 glass. The crystal structure, optical properties and photocatalytic properties of the films deposited at different temperatures were characterized by XRD, SEM, AFM, spectrophotometer and ultraviolet-visible spectrometer. The results show that TiO2 thin films prepared at 25 and 120 degrees C are amorphous, and anatase structure is obtained at 210 and 300 degrees C. As the deposition temperature increases, the grain size and surface roughness of the film increase, the transmittance of the film decreases and the lower the transmittance, the better the photocatalytic performance. The degradation rate of methyl orange solution can reach 98.97% under 24 h visible light irradiation of TiO2 film (2mm X 2mm) prepared at 300 degrees C. Increasing the sample surface area in a tiling manner can significantly increase the degradation rate of methyl orange solution.