离子交换均匀沉淀法合成纳米CeO_2研究

以Ce(NO3)3.6H2O、Na2CO3为原料,采用新型弱酸性阳离子交换树脂均匀沉淀法制备CeO2前驱体,经500℃焙烧1～4h后获得了高纯度的纳米CeO2晶体.用热重分析、X射线衍射、扫描和透射电子显微镜等对前驱体和样品的形貌和粒径分布进行了表征,并对涉及的均匀沉淀机理进行了探讨.结果表明,制备的CeO2纳米晶体属立方晶系,样品分散性好,平均粒径为30～50nm.离子交换树脂均匀沉淀法具有操作简单易行,成本低,同时避免使用有机溶剂和表面活性剂,污染小,后处理容易,离子交换树脂可再生重复使用等优点.

Preparation of CeO 2 nanoparticles by ion exchange homogenous precipitation method

Nano-crystalline particles of CeO_2 were synthesized via a novel ion exchange resin homogenous precipitation process, in which Ce(NO_3)_3 · 6H_2O and Na_2CO_3 were used as precursors and a weak acidic cation exchange resin was used as substrate. The nano-CeO_2 sample with high purity was obtained by calcination of the precipitate at 500℃ for 1-4 h. The precursors and the samples were characterized by TG-DTG, XRD, SEM and TEM techniques in terms of morphology and size distribution. The mechanism of homogenous precipitation was discussed. The XRD results indicate that the as-made CeO_2 nanocrystals are cubic crystals, consisting of crystalline particles with a size of 30-50 nm and a good dispersion. The results demonstrate that the ion exchange resin homogenous precipitation method is a simple yet environmentally benign route to the synthesis of CeO_2 nanocrystals in large scale and at low cost, in which the ion exchange resin can be recycled.