纳米氧化亚铜热力学函数的温度效应研究

Temperature Effect of Thermodynamic Function of Nano Cuprous Oxide

可控制备了Cu_2O纳米微晶,采用扫描电镜(SEM)、X-射线粉末衍射仪(XRD)对其形貌进行了表征。基于纳米材料与块体材料表面相的差异,采用原位微热量技术结合热动力学原理获取了纳米Cu_2O微晶体系与HNO3反应的动力学参数和热力学函数,并讨论了温度对其反应动力学和表面热力学性质的影响。结果表明,在298.15K时,纳米Cu_2O的摩尔表面Gibbs自由能为0.536kJ·mol^(-1)、摩尔表面焓为44.012kJ·mol^(-1)、摩尔表面熵为145.819J·mol^(-1)·K^(-1);块体Cu_2O和纳米Cu_2O的反应速率常数、标准摩尔反应焓、摩尔表面Gibbs自由能和摩尔表面焓均随着温度的升高而增大。

We controlled prepared cuprous oxide nanocrystalline,and characterized its morphology by SEM and XRD.On the basis of the difference of surface phase between nano materials and bulk materials,we obtained the kinetic parameters and thermodynamic functions of the reaction between nano cuprous oxide system and nitric acid by in situ microcalorimetry technique and thermodynamic principle.Furthermore,we discussed the influence of temperature on the reaction kinetics and surface thermodynamics of nano cuprous oxide.The results show that the molar surface Gibbs free energy,molar surface enthalpy,and molar surface entropy of nano cuprous oxide are 0.536 kJ·mol^-1,44.012 kJ·mol^-1,and 145.819 J·K^-1 at 298.15 K,respectively.The reaction rate constants,standard molar reaction enthalpy,molar surface Gibbs free energy,and molar surface enthalpy of bulk cuprous oxide and nano cuprous oxide increase with increasing of temperature.