Synthesis, characterization and optical studies of gallium activated titania nanoparticles

Abstract

The gallium ion doped and undoped titania nanocrystals were synthesized by non aqueous sol–gel technique at low temperature. They were characterized structurally and optically with the used of X-ray diffraction (XRD), Transmission electron microscopy (TEM), Scanning electron microscopy (SEM), Photoluminescence (PL) and UV–visible spectrophotometer (UV–Vis). The anatase-to-rutile phase transition was observed at 550°C and reflection peaks (101) of the tetragonal phase of each sample is shifted to lower 2θ of XRD pattern which indicates the occupancy of Ga3+ ion by substituting in Ti4+ lattice sites. Crystal lattice distortion ratios are found to decrease with increase in temperature, whereas the crystallite sizes are increased with the increase in temperature. The emission spectrum is recorded under excitation wavelength 258 nm transition of the Ga3+ ion and five emission bands at 408, 444, 468, 490 and 538 nm are observed after deconvolution of the spectra. The average decay lifetimes of this sample are found to increase as the concentration of dopant increases.