Designing and Preparing a Thin-Film Photocatalyst from Titanium Dioxide Nanotubes Codoped with Nitrogen and Fluorine

Abstract

Thin-film nanostructured coatings have been produced electrolytically from TiO₂ codoped with nitrogen and fluorine. The resulting films consist of individual TiO₂ nanotubes with the polycrystalline anatase structure; they are characterized by narrow size distribution and a high degree of local self-organization. Diffuse reflectance spectroscopy demonstrates that the absorption edge of the samples codoped with nitrogen and fluorine is shifted towards the longer wavelength region of the solar spectrum by 200 nm with respect to pure TiO₂. When irradiated with visible light, the synthesized TiO₂ films exhibit high photocatalytic activity in the reaction of phenol oxidation in aqueous media.