Fabrication of C, N-codoped TiO2 nanotube photocatalysts with visible light response

To enhance the absorption in the visible region for TiO2, C and/or N doping of TiO2 nanotube was carried out by a novel method-plasma electrolysis. The doping was achieved with active C and N produced from the plasma electrolysis of HCONH2, NaNO2, or (NH2)(2)CO. The results of XPS revealed that C and N were successfully doped into the lattice of TiO2. UV-Vis diffuse reflectance spectra showed a shift to longer wavelengths and an enhancement of the absorption in the visible region (> 400 nm) for the C, N-codoped TiO2, compared to the pure TiO2, C-doped TiO2 and N-doped TiO2. The C, N-codoped TiO2 showed the best photocatalytic activities for the degradation of methyl orange under visible light irradiation, and was a promising photocatalyst for utilizing the solar energy.