Low-temperature and one-step synthesis of rutile TiO 2 aqueous sol by heterogeneous nucleation method

Abstract

A phase-pure rutile TiO 2 aqueous sol has been prepared by heterogeneous nucleation method with an aqueous peroxotitanate solution as a precursor and SnCl 2 as rutile-phase crystalline growth promoter at a temperature as low as 100 °C in one-step process. TEM, XRD and UV–Vis spectra were used to characterize the rutile TiO 2 sol. The results reveal that a pure rutile phase TiO 2 aqueous sol with average particle sizes of around 20 nm has been synthesized, and a transparent film of rutile TiO 2 was also easily prepared by dip-coating method. Formation conditions and a possible mechanism of phase-controlling were investigated. The results show that the presence of the Sn content is essential for the formation of a pure rutile TiO 2 phase at low temperature, which involves a heterogeneous nucleation mechanism.