【摘要】 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。更多还原

【Abstract】 SiO2,CeO2 and CeO2-SiO2 mixed oxide nanometer powers were prepared by means of chemical precipitation method.Their morphology,phase structure and grain size were characterized by transmission electron microscopy and X-ray diffraction.SiO2 was amorphous structure and about 500 nm.The average size of CeO2 with cubic fluorite structure and CeO2-SiO2 mixed oxide were lower than 10 nm.This showed that the synthesis process of CeO2-SiO2 mixed oxide restricted the grain enlargement.The CeO2-SiO2 mixed oxide prepared with mass ratio of SiO2/CeO2 was 5%,10%,15% and 20%.Calcining temperature changed from 400 ℃ to 1000 ℃.Results showed that increasing SiO2 content led to a decrease in the average grain size and increasing the calcining temperature led to an increase in the average grain size.更多还原