Synthesis of brookite-type titanium oxide nano-crystals in organic media

Abstract

Thermal treatment of oxobis(2,4-pentanedionato-O,O′)titanium (TiO(acac)₂) in ethylene glycol (EG) in the presence of sodium laurate and a small amount of water at 300 °C was examined. X-Ray diffraction, transmission electron microscopy and Raman spectroscopy revealed that microcrystalline brookite-type titanium(IV) oxide (TiO₂) having an average size of 14 × 67 nm was formed and that this brookite sample was not contaminated with other TiO₂ phases such as anatase and rutile. Sodium salts, water and TiO(acac)₂ as the titanium source were indispensable for the formation of brookite crystals and the use of EG as the reaction medium was essential to avoid contamination by other phases. This brookite TiO₂ began to directly transform to the rutile phase on calcination at around 700 °C and completely converted at 900 °C.