介孔硅酸锌/氧化硅复合材料的制备与结构表征

Using mesoporous silica SBA-15 as both silicon source and assisted template, mesoporous zinc silicate/silica composites were prepared by calcining the grinding mixture of mesoporous silica SBA-15 and zinc nitrate. The samples were characterized by means of X-ray diffraction, transmission electron microscopy, and nitrogen adsorption-desorption isotherms. The results show that zinc silicate can be synthesized through the reaction between the mesoporous silica SBA-15 and the zinc nitrate encapsulated in mesopores. The reaction temperature of 800 ℃ is lower than that of the traditional solid-state reaction. The formed zinc silicates are embedded in the remained silica in the walls of the pores, which can not only increase the stability of the mesoporous structure, but also inhibit the phase transformation of the zinc silicate. Zinc silicate/silica composites possess two-dimensional ordered hexagonal mesoporous structure. The mesoporous zinc silicate/silica composites with different zinc silicate weight percentages show the pore size between 3.7 and 6.1 nm and the specific surface area between 360 and 640 m2/g.