Synthesis and Characterization of Nanocrystalline TiO₂ Doped with 2 at.% Sc³⁺ and V⁵⁺ Ions

Nanoparticles of anatase TiO2 doped with 2 at.% Sc3+ and 2 at.% V5+ ions were synthesized by sol-gel method. Average crystal sizes of TiO2, TiO2+2 at.% Sc, TiO2+2 at.% V and TiO2+2 at.% (Sc+V) calculated from XRD patterns are 18.0, 16.9, 18.0, 16.2 nm, respectively. HRTEM images of TiO2 and TiO2+2 at.% (Sc+V) exhibit well-defined lattice fringe. The lattice spacings of TiO2 and TiO2+2 at.% (Sc+V) are both measured to be 3.3 Å, which correspond to the distance between the (101) planes of anatase TiO2. Raman spectra of the samples demonstrate the well dispersion of Sc3+ and V5+ ions in the TiO2 matrix. UV-vis diffuse reflectance absorption spectra of the samples show the characteristics of TiO2, and the diffuse reflectance spectra of TiO2+2 at.% V and TiO2+2 at.% (Sc+V) exhibit red shifts and weak wide absorptions in the visible region of 400-600 nm.