Preparation of TiO2 Nanoparticles Via Glycolate Route and Effect of Addition of Alcohol on Particle Morphology

Abstract

Various methods have been employed to improve the size and properties of the TiO_2 nanoparticles so as to enhance the performance of TiO_2 based materials. In the present work TiO_2 nanoparticles have been synthesized via the glycolate route. We have studied the effects of tertiary-Butanol as a capping agent to limit the size of the TiO_2 nanoparticles. Glycolate route involves the formation and subsequent calcination of Titanium-glycolate (TiG) coordination complexes. This method offers advantages in terms of phase purity and formation of mono-dispersed particles. Titanium(IV) butoxide, Ti[O(CH2)3CH3]4 was added to a mixture of Ethylene Glycol and tert-Butanol and heated at 160°C for 2 hrs with constant stirring using a magnetic stirrer. The alkoxide was transformed into the glycolate complex. The crystallites could be readily collected as precipitates after the reaction solution had been cooled down to room temperature. The formation of TiG is confirmed by FT-IR. The molar ratios of Titanium(IV) butoxide : Ethylene Glycol : tert-Butanol were varied for different samples. In each case the TiG precursor formed is further characterized by DTA and TGA. By calcining at 500 °C and 850 °C temperatures, each TiG precursor could be transformed into anatase and rutile phases of TiO2, respectively. The crystal structure, lattice parameters and the average crystallite size of the samples have been calculated using X-ray diffraction pattern and TEM, respectively. The particle size has decreased as the ratio of tert-Butanol : EG increases. This is a confirmation of the capping properties of the tert-butanol.