Synthesis of ultrafine TiO2 by citrate gel method

A gel was formed when a mixture of TiOCl2 and citric acid is heated on a water bath. An ultrafine powder of TiO2 in the anatase phase is formed, when the gel was decomposed at 623 K. The anatase phase is converted into rutile phase on annealing at higher temperatures >773 K. These powders are characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and surface area measurements. The average particle size obtained for anatase phase is 3.5 nm whereas it is 45 nm for rutile phase.