Visible light-driven nitrogen doped TiO2 nanoarray films: Preparation and photocatalytic activity

Highly ordered aligned nitrogen doped titania nanotubes array films have been successfully prepared by liquid phase deposition (LPD) method. A new band gap in visible light region (570 nm) corresponding to 2.17 eV could be formed by nitrogen doping. Effects of anodic alumina membrane type on the morphology of titania films have been studied. Using the membrane with a certain volume fraction of Al2O3 (less than 0.71), the ordered aligned titania nanotubes were obtained. Otherwise, titania existed as ordered aligned nanorods. Under the irradiation of light with wavelength larger than 410 nm, the photocatalytic activity of nitrogen doped TiO2 nanotube film was 3 times greater than that of pure TiO2 film due to the high visible light absorption. Furthermore, TiO2 nanotube film exhibited much higher photocatalytic activity than the TiO2 nanorod film.