粒径可控纳米CeO2的微乳液法合成

Size Controlled Synthesis of CeO_2 Nanoparticles by a Microemulsion Method

以十六烷基三甲基溴化铵(CTAB)/正丁醇/正辛烷/硝酸铈(Ce(NO3)3)水溶液(氨水)所形成的反相微乳液体系合成CeO2前驱体,利用热重(TG)和X射线衍射(XRD)分析方法确定了得到纳米CeO2的适宜焙烧温度为550℃,CeO2前驱体经550℃焙烧后得到纳米CeO2.采用XRD、透射电镜(TEM)、紫外-可见(UV-Vis)分光光度计等表征手段分别对纳米CeO2的晶形、形貌、粒径及紫外吸收性质进行了表征,该纳米CeO2粒子具有立方晶型结构,分散性较好、粒径范围为5-18nm.考察了微乳液中正辛烷与正丁醇质量比、Ce(NO3)3浓度对纳米CeO2粒径的影响,结果表明:利用微乳液法,通过改变微乳液中正辛烷与正丁醇质量比、Ce(NO3)3浓度能够对纳米CeO2粒径进行有效控制;纳米CeO2的粒径均随着正辛烷与正丁醇质量比和Ce(NO3)3浓度的增大而减小.同时,对不同条件下制得的纳米CeO2的紫外吸收性质进行了考察.

Precursors of CeO2 were synthesized in a reverse microemulsion composed of cetyltrimethylammonium bromide（CTAB）,1-butanol,1-octane,Ce（NO3）3 brine（ammonia）.The optimum calcination temperature（550 ℃） was derived from thermogravimetry（TG） analysis and X-ray powder diffraction（XRD）.The CeO2 nanoparticles were then prepared by calcining the precursors at 550 ℃.The structures,morphologies,size,and UV absorption properties of the CeO2 nanoparticles were characterized by XRD,transmission electron microscopy（TEM）,and UV-Vis spectroscopy.Cubic crystalline CeO2 nanoparticles of 5-18 nm in size and with good monodispersity were obtained using this method.The influences of the mass ratio of 1-octane to 1-butanol and the concentration of Ce（NO3）3 on the size of the CeO2 nanoparticles were studied.Results showed that CeO2 nanoparticle size was dependent on the mass ratio of 1octane to 1-butanol and the concentration of Ce（NO3）3.The size of the CeO2 nanoparticles decreased as the mass ratio of 1-octane to 1-butanol as well as the concentration of Ce（NO3）3 increased.In addition,we studied the UV absorption properties of the CeO2 nanoparticles by UV-Vis spectroscopy.