Synthesis of nanocrystalline TiO₂ by tartarate gel method

Abstract

A gel was formed when a mixture of TiOCl₂ and tartaric acid was heated on a water bath. Ultrafine powders of TiO₂ in the anatase phase were formed, when the gel was decomposed at 623 K and the mole ratio of tartaric acid to titanium was 2. The anatase phase was converted into rutile phase on annealing at higher temperatures, > 773 K. When initial ratio of titanium to tartaric acid was < 2, the decomposition of gel leads to the formation of mixed phases of rutile and anatase. However, pure rutile phase was not formed by the decomposition of gel for any ratio of tartaric acid and titanium. These powders were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and surface area measurements. The average particle size obtained for anatase phase was 3 nm whereas it was 30 nm for rutile phase. Raman scattering experiments were also performed to confirm both anatase and rutile phases.