Comparative Study on Properties of Nanostructured Titania Synthesized by Colloidal and Polymeric Sol- Gel Routes

Nanostructured titania was synthesized by colloidal and polymeric sol-gel routes. Stable colloidal and polymeric titania sols were prepared by adjusting the proper values of the acid/alkoxide and the water/alkoxide molar ratios. The properties of sols were determined by dynamic light scattering technique and synthesized titania was characterized by thermogravimetry and differential thermal analysis, X-ray diffraction, Fourier transform infrared spectroscopy, optical microscopy and field emission scanning electron microscopy. The results showed particle size distribution of colloidal sol 10-50 nm compared to polymeric one which was 0.5-2 nm. Phase analysis of the colloidal sample revealed anatase as the major phase up to 550 °C, while the polymeric route resulted only anatase phase up to 750 °C. On the basis of results, titania prepared by the polymeric route showed better thermal stability against phase transformation than the sample prepared by the colloidal route. Also, microstructural studies showed that titania nanopowder can be produced by both sol-gel routes.