Preparation and characterization of nitrogen-doped titanium dioxide

Abstract

To extend the absorption range of titanium dioxide into the visible-light region, the nitrogen incorporation process is investigated. This work presents a simple procedure for preparing nitrogen doped titanium dioxide nanocrystal (TiOxNy) by calcinating the mixture of Degussa P-25 (DP-25) TiO2 and NH4Cl at temperatures between 350 and 500 degrees C under airtight condition. Analysis of X-ray photoelectron spectroscopy indicated the molecular state nitrogen was incorporated into TiO2 lattice leading to the observable shift of the absorption edge to longer wavelength region with higher absorption intensity. These TiOxNy samples exhibit photocatalytic activity for methylene blue decomposition in aqueous solution under visible light irradiation. The correlation between the photocatalytic activity of TiOxNy and nitrogen content, rutile phase composition, and surface area was investigated and discussed.