物理化学学报 >> 2006, Vol. 22 >> Issue (04): 492-495.doi: 10.3866/PKU.WHXB20060420

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反应温度对Ce2(C2O4)3•10H2O粉体形貌和形成机理的影响

梅燕;韩业斌;聂祚仁   

  1. 北京工业大学材料科学与工程学院, 北京 100022
  • 收稿日期:2005-08-29 修回日期:2005-10-31 发布日期:2006-04-10
  • 通讯作者: 聂祚仁 E-mail:zrnie@bjut.edu.cn

The Influence of Reaction Temperature on the Morphology and Formation Mechanism of Ce2(C2O4)3•10H2O Powders

MEI Yan;HAN Ye-Bin;NIE Zuo-Ren   

  1. College of Materials Science and Engineering, Beijing University of Technology, Beijing 100022, P. R. China
  • Received:2005-08-29 Revised:2005-10-31 Published:2006-04-10
  • Contact: NIE, Zuo-Ren E-mail:zrnie@bjut.edu.cn

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摘要： 以Ce(NO3)3•6H2O和草酸二甲酯(DMO)为原料, 在反应温度为30、50、65和85 ℃时, 利用均相沉淀法合成了不同形貌的CeO2超细前驱体Ce2(C2O4)3•10H2O. 利用X射线衍射分析(XRD)、透射电子显微镜(TEM)及热重-差热分析法(TG-DTA)等测试手段, 对不同反应温度合成的产物物相、形貌及性质进行了表征. 实验结果表明, 所得产物均为单斜晶系的Ce2(C2O4)3•10H2O, 且随反应温度的升高, 产物的晶化度增加; 反应温度直接影响产物的形貌及大小, 当反应温度为30、50、65和85 ℃时, 所得产物形貌分别为无规则外形、类球状、大米粒状及片状, 说明反应过程是温度敏感过程; 温度对沉淀粒子形成的影响机理实际上要归结于温度对成核速率及生长速率的影响, 此过程遵循LaMer模型及结晶过程的粒度分布和控制原理.

关键词: 反应温度, 均相沉淀法, 前驱体, 形貌, 机理

Abstract: Ce2(C2O4)3•10H2O powders with different morphologies were prepared by homogeneous precipitation method at different temperatures. The source materials were Ce(NO3)3•6H2O and dimethyl oxalate (DMO) with a molar ratio of 1:7.5. The phase, morphology and property of the products were characterized by XRD, TEM and TG-DTA. The results showed that the product was Ce2(C2O4)3•10H2O with a monoclinic structure, and the products′crystallization degree could be enhanced by increasing the reaction temperature. The reaction temperature had direct influences on the particle morphology and size. When the reaction temperatures were 30, 50, 65, 85 ℃, the morphologies were irregular, spherical, rice-like, sheet-like, respectively, indicating the reaction course to be temperature sensitive. The reaction mechanism actually related to nucleation velocity and growth rate of the grains, and it followed LaMer model and crystal distributions and control principle during the crystal formation.

Key words: Reaction temperature, Homogeneous precipitation method, Precursor, Morphology, Mechanism