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化学沉淀法制备了SiO2和CeO2以及复合氧化物CeO2-SiO2等纳米粉体。对粉体的形貌及物相结构、粒径大小通过TEM及XRD进行了检测分析。SiO2粉体为无定形结构,粒径约500 nm,立方萤石型结构的CeO2及复合氧化物CeO2-SiO2的平均粒径小于10 nm,说明复合氧化物的合成过程抑制了粒径的长大。制备了SiO2/CeO2质量比分别为5%、10%、15%、20%的复合氧化物,煅烧温度为400℃～1000℃,结果显示随着SiO2比例的增加,CeO2的特征峰在逐渐减弱,半高宽变宽,粒径变小;随着煅烧温度的升高,特征峰强度增加,半高宽变窄,颗粒的晶型发育越来越完善,但样品的粒径变大。
The chemical precipitation method was used to prepare nano-powders of SiO2 and CeO2 and composite oxide CeO2-SiO2. The morphology and phase structure of the powder, particle size by TEM and XRD were analyzed. SiO2 powder has an amorphous structure with a particle size of about 500 nm. The average particle diameter of the cubic fluorite-type CeO2 and the composite oxide CeO2-SiO2 is less than 10 nm, indicating that the synthesis of the composite oxide inhibits the growth of the particle size . The composite oxides with SiO2 / CeO2 mass ratios of 5%, 10%, 15% and 20% were prepared and the calcination temperature was between 400 ℃ and 1000 ℃. The results showed that the characteristic peak of CeO2 gradually weakened with the increase of SiO2 ratio , Broadening the FWHM and decreasing the particle size. As the calcination temperature increases, the intensity of the characteristic peak increases and the FWHM narrows. The crystal growth of the particles is more and more perfect, but the particle size of the sample becomes larger.