A novel approach for the synthesis of visible-light-active nanocrystalline N-doped TiO2 photocatalytic hydrosol

A visible-light-active nitrogen doped nanocrystalline titanium dioxide (N-TiO2) hydrosol was prepared by precipitation-peptization method and following with hydrothermal crystallization at 110 degrees C holding for 6 h. XPS results show that nitrogen ions have been doped into the TiO2 lattice successfully and the UV-Vis absorption spectra indicate that the light absorption edge of the N-doped TiO2 has been red-shifted into visible light region. The photocatalytic performance of the N-doped TiO2 thin film prepared from the synthesized hydrosol was evaluated by photodegrading the gaseous formaldehyde (HCHO) under visible light irradiation. The photodegradation ratio of HCHO reached up to 90% within 24 h and the degradation ratio was stable for ten degradation cycles, indicating the prepared hydrosol has good reusable performance in photodegrading gaseous pollutants. (C) 2014 Elsevier Masson SAS. All rights reserved.