XAS study of TiO2-based nanomaterials

• XAS studies of the W and Mo-doped TiO2 nanoparticle specimens were presented.
• The Ti:K edge spectra in the XANES range show features characteristic for anatase.
• The Mo and W XANES spectra do not show noticeable changes with doping level.
• A decrease of the amplitude of the EXAFS function with doping is observed.
• The EXAFS functions decrease the second-neighbour peak with increasing Mo content.

X-Ray Absorption Spectroscopy studies of the W (0–1 at% W) and Mo-doped TiO2 (0–1 at% Mo) nanoparticle specimens at the K edges of titanium and molybdenum as well as at the L2 L3 edges of tungsten are presented. The materials were prepared with Flame Spray Synthesis process by oxidation of metal-organic precursors. The Ti:K edge spectra in the XANES range show pre-edge and post-edge features characteristic for anatase. A decrease of the amplitude of the EXAFS function with doping is observed and attributed to a softening of the crystal lattice. The Mo EXAFS functions show a considerable decrease of the second-neighbour-shell peak with increasing Mo content, which is attributed to an increased number of cation vacancies. For tungsten a less pronounced effect is observed. The Mo and W XANES spectra do not show noticeable changes with doping level, which indicates their unchanged oxidation states.