The Wo <sub> 3 </ Sub> And Of Wo <sub> 3 </ Sub>-sio <sub> 2 </ Sub> Preparation And Characterization Of Mesoporous Materials

Mesoporous molecular sieve is a new kind of porous materials, with high surface area, regular array of uniform channels, ordered pore arrangement and tunable pore dimensions. In recent years mesoporous materials had been paid widely attentions in the fields of catalysis, adsorption, separation, preparation of nano materials and so on. In this thesis, we focused on the synthesis of mesoporous materials with different components, structures, morphologies and pore sizes by using cationic surfactant (CTAC) and nonionic surfactant block copolymer(P123) as the structure directing agents. Such materials obtained may have great theoretical and practical significance, and significant efforts are devoted to the development of potential applications in optoelectronics, sensing, bioseparation, drug delivery, environmental cleanup and so on. This thesis is arranged as the following:Mesostructured tungsten oxide is synthesized by hydrolytic condensation at room temperature and hydrothermal technique, employing cationic surfactant cetyl trimethyl ammonium chloride(CTAC) as template and using sodium tungstate as inorganic precursor. The effects of the mol ratio of CTAC and sodium tungstate, the value of pH, hydrotherm time, hydro-therm temperature and calcination have been investigated in detail.Mesoporous tungsten trioxide materials are synthesized by solvent hydrothermal technique, employing nonionic surfactant block copolymer (P123) as template, using tungsten hexachloride as inorganic precursor and ethanol as solvent. Several methods are employed to characterize the structure of the mesoporous materials. And the effects of time and temperature have been investigated in detail.Mesoporous silicon dioxide materials are synthesized by hydrothermal technique, employing nonionic surfactant block copolymer(P123) as template and using ethyl silicate as inorganic precursor. Several methods are employed to characterize the structure of the mesoporous materials. The materials have a BET surface area of 596.27m²·g^-1, a pore volume of 0.95cm³·g^-1 and an average pore diameter of 7.00nm with a pore distribut- ion centered at 9.29nm.Mesoporous silicon dioxide materials including tungsten are synthesized by hydrothermal technique, employing nonionic surfactant block copolymer(P123) as template, using ethyl silicate as inorganic precursor and sodium tungstate as the origin of tungsten. Several methods such as X-ray diffraction(XRD), high resolution transmission electron microscop-y(HRTEM), energy dispersive X-ray spectroscopy (EDX), ultraviolet-visible diffuse reflectance spectra(UV-vis-DRS), fourier transform infrared spectra(FT-IR), laser raman spectra(Raman) and nitrogen adsorption-desorption isotherms are employed to characterize the structure of the mesoporous materials. And the existent shape of tungsten in the mesoporous materials including more and more tungsten has been investigated in detail.