Influence of particle size on the phonon confinement of TiO₂nanoparticles

Abstract

Titanium dioxide nanocrystals are prepared by a hydrolysis process of Titanium tetraisopropoxide. Nano crystals of various sizes are obtained after annealing from 300 to 450°C. Raman scattering was employed to investigate the evolution of the anatase phase in the nano crystals during annealing. X-ray diffraction, transmission electron microscopy and dynamic light scattering studies were done to supplement the Raman scattering results on particle size. Phonon confinement and non-stoichiometry effects are responsible for the blue shift and broadening of the lowest-frequency Eg Raman mode.