Synthesis Of Mesoporous TiO₂ Using Templates And Its Functionalization

Non-silicon-based ordered mesoporous materials in recent years has been the emergence of a new research focus. TiO₂ as an important transition metal oxides in their unique photocatalytic activity, such as UV-shielding effect function, as well as the chemical properties of stability, low toxicity, inexpensive and easy to recycle the characteristics of non-silicon-based mesoporous materials research focus.At present, the synthesis of mesoporous TiO₂ product of the presence of poor channel in orderly, stable, and can hardly be less than ideal crystalline skeleton of the problem. In this paper, through the use of different methods of synthesis of mesoporous TiO₂, and the structure of the nature of the product and its influencing factors and removal of template suitable manner to be studied, but also a photocatalysis, as well as the supported heteropoly acid functional studies.The major research includes the following aspects:(1) Mesoporous TiO₂ was synthesized by using cetyltrimethyl ammonium bromide (CTAB) as a template and anhydrous ethanol and tetra-n-butyl titanate (TBOT) as precusor.The mesoporous TiO₂ materials were obtained by surfactant-mediated sol-gel method. The relation between reaction temperature, calcination temperature, the amount of template, aging time for the mesoporous structure is studied in the paper. Mesoporous TiO₂ were characterized by using FT-IR, XRD, HRTEM, and N₂ adsorption - desorption isotherms. The results show that mesoporous TiO₂ prepared with short-range order of the worm-like holes, than the surface area and pore volume of 137.5 m²Â·g^-1 and 0.223 cm³Â·g^-1.(2) Ordered Mesoporous TiO₂ was synthesized by using CTAB as a template and using anhydrous ethanol and TBOT as precusor.The Ordered mesoporous TiO₂ materials were obtained by alcohol-thermal method. the relation between reaction temperature, reaction time, the amount of template for the mesoporous structure was studied in the paper. Mesoporous TiO₂ were characterized by using FT-IR, SXRD, HRTEM, and N₂ adsorption - desorption isotherms. The results showed that the preparation of mesoporous TiO₂ with the pore structure in an orderly manner, and a very narrow distribution, surface area and pore volume of up to 325 m²Â·g^-1 and 0.4580 cm³Â·g^-1.(3) This chapter through the methylene blue photodegradation experiments to study the different between these two kinds of synthetic Methods for mesoporous TiO₂ photocatalytic properties. The result indicates that the best of degradation condition is the amount of photocatalyst 1%,methylene blue initial concentration 30mg/L and pH=7. the sol-gel mesoporous TiO₂ photocatalytic activity than the preparation of alcohol-thermal method mesoporous TiO₂.(4) The two types of mesoporous TiO₂ phosphotungstic acid to the load test, by using IR, surface area and other means of characterization. Phosphotungstic acid study in two mesoporous TiO₂ immobilized on the carrier properties. The results show that the melting of the solid catalyst from the previous 3 h is very large, 4 h after the dissolution reached from the volume of desorption balance; the same vector, the same solvent, Immobilized phosphotungstic acid catalyst on mesoporous TiO₂ which though sol-gel method dissolved off larger; the same vector containing, the same proportion of solid, the solid contained in phosphotungstic acid dissolved in the water off larger.The experimental results provide useful information for immobilized phosphotungstic acid catalyst and its application.