RAMAN STUDY OF VANADIUM-DOPED TITANIA NANOPOWDERS SYNTHESIZED BY SOL-GEL METHOD

Pure titania ( TiO 2 ) nanopowders and TiO 2 doped with 10 mol % of vanadium ions ( V 3+ ) are synthesized by sol-gel method. The dependence of structural characteristics of nanopowders on synthesis conditions is investigated by X-ray diffraction and Raman spectroscopy. Very intensive modes observed in Raman spectra of all nanopowders are assigned to anatase phase of TiO 2 . Additional Raman modes of extremely low intensity which can be related to the presence of small amount of brookite amorphous phase are observed in pure TiO 2 nanopowders. In V -doped nanopowders anatase was the only TiO 2 phase detected. The variations in duration and heating rate of calcination influence slightly the Raman spectra of pure TiO 2 , but have a great impact on Raman modes of anatase, as well as the additional Raman modes related to the presence of vanadium oxides in V -doped samples.