Fabrication of anatase-type TiO2 films by reactive pulsed laser deposition for photocatalyst application

TiO2 films having anatase crystal structure were prepared on glass substrates by reactive pulsed laser deposition using a metallic Ti target in an O2 gas ambient. At a fixed substrate temperature of 400 °C, the crystalline structure, surface morphology, optical properties and photocatalytic activity of the TiO2 films were greatly affected by the O2 gas pressure. It was found that nearly pure anatase-phase TiO2 film can be obtained under an O2 pressure of 15 Pa, which had smallest grain size among the films deposited under various O2 gas pressure from 5 to 30 Pa. This film also showed good optical transmittance between the wavelength of 200 and 800 nm and high photocatalytic efficiency on the decomposition of methylene blue in aqueous solution. Discussions were given to explain the experimental phenomena.