Nitrogen and europium doped TiO2 anodized films with applications in photocatalysis

Micro-arc oxidation method is a useful process for mesoporous titanium dioxide films. In order to improve the photocatalytic activity of the TiO2 film, N–Eu co-doped titania catalyst was synthesized by micro-arc oxidation in the H2SO4/Eu(NO3)3 mixture solution.The specific surface area and the roughness of the anodic titania film fabricated in the H2SO4/Eu(NO3)3 electrolyte, were increased compared to that of the anodic TiO2 film prepared in H2SO4 solution. The absorbance response of N–Eu titania film shows a higher adsorption onset toward visible light region, and the incorporated N and Eu ions during anodization as a dopant in the anodic TiO2 film significantly enhanced the photocatalytic activity for dye degradation. After dye decomposition test for 3 h, dye removal rates for the anodic TiO2 film were 60.7% and 90.1% for the N–Eu doped titania film. The improvement of the photocatalytic activity was ascribed to the synergistic effects of the surface enlargement and the new electronic state of the TiO2 band gap by N and Eu co-doping.