Porous N-doped TiO2 nanotubes arrays by reverse oxidation of TiN and their visible-light photocatalytic activity.

Abstract Highly ordered porous N-doped TiO 2 nanotubes arrays (N-TiO 2 NTAs) are produced via reverse oxidation of porous TiN NTAs in air atmosphere. The band gap of produced porous N-TiO 2 NTAs was reduced from 3.04 eV for TiO 2 NTAs to 2.94 eV. Photocatalytic (PC) investigations indicate that the porous N-TiO 2 NTAs exhibit three times larger visible light PC kinetic rate constant than that of anatase TiO 2 NTAs as a result of the enhanced visible light activity and the large surface area. The results demonstrate that reverse oxidation of nitride is an applicable method for the preparation of nitrogen doping oxide and could be potential using for the fabrication of other carbon or sulfur doped oxide by oxidation of corresponding carbide and sulfide for high efficient visible light photocatalyst. Highlights • Mesoporous N-doped TiO 2 NTAs were fabricated by reverse oxidation of TiN NTAs. • The nitrogen content in TiO 2 NTAs was controlled by oxidation condition. • The porous N-TiO 2 NTAs exhibit enhanced PC activity tha n that of bare TiO 2 NTAs. • High PC activity is due to the porous structure and good visible light response. [ABSTRACT FROM AUTHOR]