Effect of Nd3+ doping on structure, microstructure, lattice distortion and electronic properties of TiO2 nanoparticles

Doped and undoped TiO2 nanoparticles were prepared by Stober method and thermally treated at 600 degrees C. The effect of Nd3+ ion on the structure and microstructure of anatase-phase TiO2 nanocrystals was studied by Rietveld refinement method using X-ray powder diffraction data. Bond lengths, bond angles, and edges distances were analyzed. The phase formation was confirmed by high-resolution transmission electron microscopy. The adjustment of Ti-O bond length induced by the addition of Nd3+ ions, reduced the octahedral distortion and altered the octahedral array in the anatase-phase TiO2 nanocrystal. The changes of structure and microstructure were mainly observed for TiO2 nanoparticles doped with 0.1 at.% of Nd3+ ions and attributed cationic substitution of Ti4+ ions which promoted changes in the density of states and gap band of TiO2. The dopant insertion resulted in a better structural stability of the nanocrystals that enhanced their charge transference and photocatalytic efficiency.