粒径可控纳米CeO_2的微乳液法合成

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.

Size Controlled Synthesis of CeO_2 Nanoparticles by a Microemulsion Method

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 1-octane 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.