溶胶-凝胶自蔓延燃烧法合成纳米尖晶石型AFe2O4

摘要

A series of nano spinels AFe2O4 (A=Cu, Co, Ni, Mg, Zn) were synthesized through sol-gel auto-combustion method.The study was focused on the influence of the different elements of A bit on the spinel materials.The prepared samples were characterized by DTA, XRD, FT-IR, BET, SEM, TEM and XPS techniques.The results showed that the dried gel of AFe2O4 auto-burned at 200 ℃.And the spinel structures which were constituted by the tetrahedron and hexahedron sublattices formed at 500 ℃.It was found that the lattices with size of around 40 nm were typical nano structures.Especially, the proportions of Fe, Cu, O in the trans spinel material CuFe2O4 were 42%, 39% and 19%.BET, TEM and SEM results showed the spinel materials had obvious lamellar mesoporous structures with specific surface areas of around 20 m2/g.With different elements in A bit, the dried gel of AFe2O4 auto-burned at different temperature, and the pore structures and microstructures had great difference.%通过溶胶-凝胶自蔓延燃烧法制备了系列纳米尖晶石材料AFe2O4(A=Cu、Co、Ni、Mg、Zn),采用DTA、XRD、FT-IR、BET、SEM、TEM、XPS等技术对样品进行了表征,着重研究不同A位元素对尖晶石材料的影响.结果表明,200 ℃时,AFe2O4干凝胶发生自蔓延燃烧;500 ℃时,尖晶石结构形成,有明显的正四面体和正六面体亚晶格出现,晶格尺寸在40 nm左右,均呈纳米结构;其中CuFe2O4为反式尖晶石结构,Fe、Cu、O所占比例分别为42%,39%,19%.BET、TEM及SEM结果发现该方法制备的尖晶石材料呈明显的片状介孔结构,比表面积在20 m2/g左右,层状结构之间距离15 nm.A位上元素不同,制备过程中自蔓延温度不同,孔结构和微观结构有较大差异.