Synthesis and characterization of tungsten oxide-doped titania nanocrystallites

The precursors of TiO2- or WO3-doped TiO2 (WO3/TiO2) nanocrystallites were prepared by the sol-precipitation method and calcined at temperatures ranging from 400 to 900 degreesC for 2 h in air. The optimum reactive conditions were determined, such as the concentration of the reactants, the kind of the surfactant, the doping quantities of tungsten oxide, the pH value, the reactive temperature and time. The average particle size, morphology and structure properties of the nanocrystallites were examined by differential thermal analysis (DTA)/thermal gravimetric analysis (TGA), X-ray diffraction (XRD), TEM, etc. The relations between the particle size and the calcining temperature or the doping quantities of WO3 are discussed, as well as the role of tungsten ions on the stability of the anatase form of the nanocrystalites. (C) 2002 Elsevier Science B.V All rights reserved.