聚乙烯吡咯烷酮调控合成特殊形貌碳酸铈

以硝酸铈Ce(NO₃)₃]为原料，碳酸氢铵（NH₄HCO₃）为沉淀剂，弱阳离子表面活性剂聚乙烯吡咯烷酮（PVP）为软模板剂，通过控制初始PVP浓度、加料反应时间、陈化时间制备得到颗粒均匀、类似花状结构的碳酸铈Ce₂(CO₃)₃]粒子。采用扫描电子显微镜（SEM）、X射线衍射仪（XRD）、傅里叶红外光谱仪（FTIR）对制得的碳酸铈样品进行分析表征。结果表明，制备颗粒均匀、形状规则的花状碳酸铈粒子的最佳条件为：初始PVP浓度为2g/L，加料反应时间为1h，搅拌速度为300r/min，陈化时间为4h。并对PVP调控合成特殊形貌碳酸铈的调控机理进行了初步探究：PVP 通过酮基中的O吸附在碳酸铈晶体表面，阻碍了(002)和(040)晶面的生长，限制了晶体晶面的生长速度，从而调控碳酸铈的形貌。XRD结果表明最终产物为八水合碳酸铈。

Synthesis of cerium carbonate with special morphology controlled by polyvinylpyrrolidone

Cerium carbonate Ce₂(CO₃)₃] particles with flower-like structure were prepared from cerium nitrateCe(NO₃)₃] as raw material, ammonium bicarbonate（NH₄HCO₃) as precipitator and polyvinylpyrrolidone (PVP) as soft template by controlling initial PVP concentration, feeding reaction time and aging time. The cerium carbonate samples were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The results showed that the optimum conditions for the preparation of flower-like cerium carbonate particles with uniform particle size and regular shape were as follows: initial PVP concentration was 2g/L and feeding reaction time was 1h with stirring speed of 300r/min at aging time of 4h. The mechanism of controlling the synthesis of cerium carbonate with special morphology by PVP was preliminarily explored. PVP adsorbs on the surface of cerium carbonate crystal through oxygen in ketone group, which hinders the growth of (002) and (040) crystal planes and limits the growth rate of crystal planes, thus regulating the morphology of cerium carbonate. The final product was organic-inorganic composites of PVP and Ce₂(CO₃)₃·8H₂O.