A new sight on hydrogenation of F and N-F doped {001} facets dominated anatase TiO2 for efficient visible light photocatalyst

Nonmetal doping such by N and F has been studied widely to enhance the visible light photoactivity of TiO2. Recently, hydrogenation of pure and N doped TiO2 is also well studied by theoretical calculations. However, little experimental evidence is known about the nature of the hydrogenation effect played on F and N-F doped anatase TiO2. In this study, hydrogenation of F and N-F doped {001} facets dominated anatase TiO2 were prepared by annealing the doped photocatalysts in the 10-bar H-2 atmosphere. Electron paramagnetic resonance (EPR) spectra confirmed the presence of different coordinated Ti3+ and oxygen vacancies located in the hydrogenated N and N-F doped TiO2 as a result of removing the already located N and F species. The visible-light photocatalytic activity of hydrogenated N-F doped TiO2 was significantly enhanced because of the formation of defect energy state belts and disorder structures. This study gives a new sight on the interaction between H and N, F species in doping TiO2 and developing efficient visible light photocatalyst by hydrogenation. (C) 2012 Elsevier B.V. All rights reserved.