尖晶石纳米粉体的微晶结构与吸光特性

为开发新的性能更优异的光催化剂,采用无机盐溶胶—凝胶法制备了CoAl2O4、MgFe2O4、CoFe2O4和CoCr2O4等12种尖晶石纳米粉体。利用X射线衍射光谱仪（XRD）和紫外—可见漫反射光谱仪（UV-Vis）对其微晶结构和吸光性能进行了对比研究。结果表明,所制备纳米粉体均具有尖晶石型晶体结构,属立方晶系,Fd/3m空间群,粒子尺寸为4～17nm;其可见光吸收性能普遍优于非磁性尖晶石纳米粉体,且磁性尖晶石纳米粉体的光吸收极限波长大于800nm,禁带宽度小于1.55eV。CoAl2O4、MgFe2O4、CoFe2O4和CoCr2O4四种尖晶石型纳米粉体具有优良的可见光响应性能。

Microcosmic crystalloid structure and absorbency of spinel nano-particles

Aimed at developing new photocatalyst of superior performance,this paper describes the preparation of 12 kinds of spinel nano-powders,such as CoAl2O4,MgFe2O4,CoFe2O4 and CoCr2O4 etc,by the inorganic salt sol-gel method and the comparative study of the crystalloid structure and absorbency of the prepared samples by using the analytic technologies such as XRD and UV-Vis.The study shows that the prepared nano-powders which are of a spinel-type structure and a cubic crystal system have Fd/3m space group,and particle size ranging 4 ～ 17 nm.The prepared nano-powders have visible light absorption generally superior to that of non-magnetic spinel nanometer powders.Magnetic spinel nanoparticles have limit wavelength of light absorption more than 800 nm and band gap of less than 1.55 eV.CoAl2O4、MgFe2O4、CoFe2O4 和 CoCr2O4,the four kinds of spinel-type nano-powders exhibit excellent visible-light response performance.