From TiCl 3 to TiO 2 nanoparticles (anatase, brookite and rutile): Thermohydrolysis and oxidation in aqueous medium

Abstract

Titania nanoparticles were synthesized by hydrolysis and oxidation of titanium trichloride (TiCl 3) in aqueous medium. The TiO 2 synthesis via the hydrolysis of Ti(III) proceeds in two steps: a condensation step and an oxidation step, which can be separated or simultaneous and they could take place in both orders. The importance of the medium acidity (0.5<pH<6.5) at 60 °C on the precipitation was underlined in this study. According to the pH, brookite (diamond-shape platelets) or rutile (rods) were obtained under particularly soft conditions, as well in acidity as in temperature whereas these particles are classically obtained under drastic conditions. Moreover, the control of the TiCl 3 hydrolysis allowed the synthesis of non-usual morphologies of TiO 2 nanoparticles, especially rods of anatase, small square platelets (3 nm) of rutile.