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.