Chemical and micro structural properties of TiO2 synthesized by sol-gel procedure

Nanosized TiO2 powders were prepared using the sol-gel procedure. The selected colloidal suspensions were stabilized with polyethylene glycol (PEG). This polymer prevented sintering of TiO2 particles during the calcination of the starting material. X-ray powder diffraction (XRD) phase analysis showed that the samples, obtained up to 500°C, were a mixture of anatase and brookite. In the samples, obtained at 850°C and higher temperatures, rutile as a single phase was detected. The TGA/DTA curves were dependent on the preparation of TiO2 samples. The samples were also characterized by Fourier transform infrared spectroscopy and laser Raman spectroscopy. A new method, based on low-frequency Raman scattering, was proposed for the size determination of nanosized TiO2. The size determination of nanosized TiO2 by low-frequency Raman scattering was in a good agreement with crystallite size values obtained by XRD.