Synthesis Of Mesoporous Titania Using Templates And Its Structural Modifications

The study in this thesis was focused on the synthesis and structural modification of mesoporous titania in view of the current problems and difficulties in this area. The goal is to provide new and efficient routes for obtaining ordered, stable and potentially useful mesoporous TiO2 materials by using different templates under proper preparing methods and conditions.Mesoporous TiO2 powders were prepared by hydrolysis condensation process using a non-ionic surfactant TX-100 as template with tetrabutyl orthotitanate (TBOT) as precursor. The experiment results show that TX-100 was an efficient pore forming reagent. N2 adsorption-desorption analysis indicates that the as-synthesized sample had a specific surface area of 241m2?g-1 and a narrow pore size distribution concentrated between 3~6nm. The template could be easily removed by washing the precipitation with water and ethanol at room temperature as confirmed by FT-IR. XRD pattern demonstrates that as-synthesized product had a framework of anatase phase. The mesoporous titania could efficiently degrade methyl orange under UV irradiation and showed a higher photocatalytic activity than non-porous nano titania. Effects of calcination on crystallinity, pore structure and photocatalytic activity were also studied. The photocatalytic activity of the material were further improved by doping Fe(III) to its framework.Ordered mesoporous titania was obtained using cetyltrimethylammonium bromide as template through a hydrothermal process. The influence of Fe-doping on the pore structure of mesoporous titania was studied by small-angle X-ray diffraction and N2 adsorption-desorption analysis. The ordering degree and the thermal stability of the mesostructure were improved after the incorporation of iron into TiO2 skeleton. A large specific surface area(418m2?g-1) and a more uniform pore distribution were obtained for the Fe-doped mesoporous TiO2.Mesoporous TiO2 was also prepared by hydrolysis condensation process using block copolymer P123 as the template. Small-angle XRD pattern shows that the as-synthesized material possessed ordered pore channels. Main factors which affected the pore ordering were studied. The template could be efficiently...