Preparation of Mesoporous Titania via Templating with Surfactants

Abstract

When titanium tetra-isopropoxide (TTIP) is dissolved in a hydrochloric solution, a transparent titania sol solution forms. The precipitate of titania is obtained by aging the mixing solution of the titania sol and a surfactant for 48 hours at 60°C.
In the presence of SDS, the formation rate of the precipitation increases with increasing SDS to TTIP molar ratio, and the crystal structure of titania changes from rutile to anatase. The specific area and pore volume of the calcined titania are larger than that of the titania prepared in no surfactant. The results show that SDS functions as a template to prepare the mesoporous titania. Under TTIP: SDS=1: 1, the powder XRD pattern of the as-synthesized precipitate has a peak at 2θ=3.2°. The result shows that the precipitate has a regular microstructure of nanometer size, but the microstructure is destroyed by the calcination. In both cationic and nonionic surfactants systems, the structure of titania is rutile, because the formation rate of precipitate is very slow. The specific surface area and pore volume are almost the same as that prepared with out surfactant. These results show that both surfactants don't function as templates.