Investigation of nitrogen doped TiO2 photocatalytic films prepared by reactive magnetron sputtering

Nitrogen doped titanium oxide films were loaded on aluminum substrates by reactive magnetron sputtering with O-2/N-2 mixture as reactive gas. Surface molecularly chemisorbed N-2, doped N3- and solid solution N-2 were found in the films by XPS experiments. The properties of the films, including crystallinity, surface morphology and light absorption capability are influenced by the O-2/N-2 ratio of reactive gas, while the photocatalytic activity is determined by the amount of doped N3- in the film. The film with optimum activity, which is about 1.5 times of that of pure TiO2 film, was obtained at N-2/(O-2 + N-2) = 80%, with concentration of doped N3- to be 0.594 at.%. (C) 2004 Elsevier B.V. All rights reserved.