不同液相法制备CeO_2粉体的对比研究

Preparation of Nanometer-Sized Ceria Powder with Different Liquid-Phase Methods

以Ce(NO3)3.6H2O为铈源,采用液相法中的氨水沉淀法、碳酸氢铵沉淀法和借助微波的溶胶凝胶法分别制备了纳米CeO2粉体。利用XRD、TEM对所得粉体进行分析表征,从晶粒大小、分散性、形貌等方面进行了对比研究,结果表明氨水沉淀法制得的CeO2粉体为球状,平均一次粒径最小仅为9.5 nm,且分散性最好。利用IR确定了碳酸氢铵沉淀法中前驱体的物相组成,并讨论了棒状CeO2的形成过程,发现在形貌上与其前驱体具有继承性。

Nanometer-sized ceria powder was respectively prepared with chemical precipitation and sol-gel methods, both using cerium nitrate hexahydrate as a starting material. Ammonia and ammonium bicarbonate were separately used as precipitating agent in chemical precipitation method and microwave was applied in sol--gel method. Ceria powder was characterized using XRD and TEM. The relative studies on the grain size, powder agglomeration and morphology were carried out. Results showed that the smallest and best dispersed spherical ceria powder with average diameter of 9. 5nm could be obtained using ammonia as precipitating agent. Phase composition of precursor was confirmed by IR and the formation process of rod -like ceria powder was discussed when used ammonium bicarbonate as precipitating agent. It was found that the successive relationship of morphology between ceria and its precursor existed.