介孔硅酸锌/氧化硅复合材料的制备与结构表征

Synthesis and structure characterization of mesoporous zinc silicate/silica composites

以介孔氧化硅SBA-15作为硅源和辅助模板,将SBA-15与硝酸锌研磨混合,采用高温固相法制备出介孔硅酸锌/氧化硅复合材料。采用X射线衍射,透射电子显微镜,氮气吸、脱附技术对样品的结构进行表征。研究结果表明:SBA-15与引入到孔道中的硝酸锌发生固相反应生成硅酸锌,800℃的煅烧温度较传统固相反应温度有显著下降。硅酸锌镶嵌在孔壁上剩余的氧化硅中,不仅能够提高介观结构的稳定性,而且能够抑制硅酸锌发生相转变。硅酸锌/氧化硅复合材料具有二维六方有序介孔结构;含不同质量分数硅酸锌的硅酸锌/氧化硅复合材料的孔径为3.7~6.1nm,比表面积为360~640m^2/g。

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 6.1nm and the specific surface area between 360 and 640m-2/g.