Synthesis of Mesoporous Titania with Surfactant and its Characterization

Abstract

A mesoporous titania was obtained by gelation from Ti-alkoxide in acidic solutions with addition of surfactant cetyltrimetylammonium bromide (CH₃(CH₂)₁₅N(CH₃)₃Br) using a sol-gel process. The effects of surfactant concentration on synthesis of mesoporous titania were studied. The structural characterisation was studied by differential thermal analysis, infrared spectroscopy, X-ray diffraction. Studies by X-ray diffraction showed that crystallisation of TiO₂ powder occurs at 200°C, above 200°C we obtained a mixture of two forms-Anatase and rutile. The textural characterisation by nitrogen adsorption-desorption allowed us to observe the variation of the surface area, porous volume and pore diameters according to temperature and [CTAB]/[Ti-alkoxide] molar ratio. The analysis of the results shows that addition of surfactant residue increases considerably its pore diameters. The deposit thin layers has been realized with a sol prepared with the destabilization of colloidal solutions process. Scanning electron-spectroscopy observation for thermally treated (at 400 and 600°C) samples, showed homogeneous layers without cracking.