An improvement on sol-gel method for preparing ultrafine and crystallized titania powder

Abstract

TiO₂ nanoparticles were prepared using a sol-gel method with inorganotitanates and polyethylene glycol (PEG). However, the way TiO₂ particles were obtained from the dry gel was not by calcining but by redissolving the dry gel which had been treated at 100°C, thereby releasing the particles. The TiO₂ powder prepared in this manner was ultra-fine (∼4 nm) and crystallized (anatase phase) merely by being exposed to 100°C while inside the gel. It was supposed that this low temperature crystallization of TiO₂ results from the special structure of the gel which formed through the linking of TiO(NO₃)₂ · H₂O with PEG chains by a hydrogen bond. This preparation method also has an advantage in environmental protection.