Ag3PO4溶解热力学函数的晶面效应与温度效应

在室温下制备了立方体{100}、 四面体{111}、 菱形十二面体{110}和块体Ag₃PO₄微晶, 并进行了表征. 测定了其在不同温度下水溶液中的电导率, 结合强电解质溶液和溶解热力学理论, 得到了Ag₃PO₄微晶的溶解热力学函数. 以具有不同晶面的Ag₃PO₄微晶为模型, 研究了纳米材料溶解热力学函数的晶面效应和温度效应. 结果表明, 具有{110}晶面的菱形十二面体Ag₃PO₄的标准摩尔溶解吉布斯自由能()、 标准摩尔溶解焓()和标准摩尔溶解熵()最大, 具有{100}晶面的立方体Ag₃PO₄次之, 具有{111}晶面的四面体Ag₃PO₄最小; 溶解平衡常数(K_{\mathrm{SP}})和随着温度的升高而增大.

Facet and Temperature Effects on Dissolution Thermodynamic Functions of Ag3PO4 Microcrystals†

Ag₃PO₄ microcrystals with different facets, such as {100}(cubic), {111}(tetrahedron), {110}(rhombohedral dodecahedron), and bulk Ag₃PO₄ microcrystals were synthesized at room temperature. Based on the difference of the conductivity between Ag₃PO₄ microcrystals with different facets, the dissolution thermodynamic function of Ag₃PO₄ microcrystals were derived via combining the theoretical formula of strong electrolyte solution and dissolution thermodynamics. According to this method, the dissolution thermodynamic functions such as standard dissolution Gibbs free energy, standard dissolution enthalpy and standard dissolution entropy of the prepared Ag₃PO₄ microcrystals were gained. Moreover, the facet effect and temperature effect on these obtained dissolution thermodynamic functions were discussed. The results revealed that the dissolution thermodynamic function of rhombohedral dodecahedron Ag₃PO₄ were maximum, followed by cubic and tetrahedron Ag₃PO₄ . Along with the increase of the temperature, dissolution equilibrium constant and standard dissolution Gibbs free energy increased.