采用反相微乳液法在室温条件下制备了尺寸、形貌高度均一的钼酸钙(CaMoO4)纳米饼,并运用X射线粉末衍射(XRD)、场发射扫描电子显微镜(FE-SEM)对其组成、结构和形貌进行了表征。利用原位微量热技术研究了所得产物与盐酸反应过程的热动力学;基于热力学势函数法设计热化学循环,并结合化学反应的过渡状态理论求算了298.15 K下产物的标准摩尔生成焓、标准摩尔生成Gibbs自由能及标准摩尔熵;基于纳米材料与对应块体材料热力学性质的本质差异,获得了产物的表面热力学性质如比表面熵、比表面焓与比表面Gibbs自由能。
CaMoO4 nanocakes with highly uniform size and morphology were prepared by reverse-microemulsion at room temperature, and were characterized by X-ray powder diffraction (XRD) and field-emission scanning electron microscopy (FE-SEM). The thermokinetic properties of the reaction system consisted of CaMoO4 and HCl were investigated via employing in-situ microcalorimetry. Combined thermochemical cycle with transition state theory, standard molar enthalpy of formation, standard molar Gibbs free energy of formation and standard molar entropy at 298.15 K for the prepared CaMoO4 nanocakes were gained. On the basis of the essential difference between thermodynamic properties of nanomaterial and its bulk material, surface thermodynamic properties of the products such as specific surface enthalpy, specific surface entropy and specific surface Gibbs free energy were successfully acquired.