Preliminary Specification of the Structure of Photoactive TiO2 by the Surfactant-Mediated Sol-Gel Method

Abstract

Small titania particles with very high surface areas could be generated from titanium(IV) isopropoxide within templates of reverse micelles of a surfactant by the sol-gel method. Aggregates of non-ionic surfactant Triton TX-100 in cyclohexane are given as an example of a suitable reverse micelle environment. Well transparent crude gels obtained by hydrolysis of the initial alkoxide could be decomposed either directly to photoactive anatase or first treated with supercritical fluid extraction to significantly reduce the content of organics in the gel structure. The effect of temperature on the extent of TiO2 crystallisation is discussed. A synthetic route to the anatase form of TiO₂ with a very high specific surface area and a well developed mesoporous and microporous structure is presented.