热分解法制备纳米粒状Pr6O11及其光吸收特性的研究

Study on Preparation of Nano-granular Pr6O11 by Thermal Decomposition and its Optical Absorption Properties

以六水草酸镨Pr2(C2O4)3·6H2O为镨源,通过热分解法制备纳米粒状Pr6O11。借助热重-差热(TG-DTA)曲线研究了六水草酸镨在空气中的热分解过程。利用X射线衍射仪、扫描电镜以及紫外-可见分光光度计分别表征了六水草酸镨在空气中热分解产物的物相、形貌和光吸收特性。结果表明,六水草酸镨在空气中的热分解过程主要分为两个阶段:第一阶段是室温~300℃,大片状六水草酸镨失去吸附水和结晶水变为小片状Pr2(C2O4)3;第二阶段是300~800℃,小片状Pr2(C2O4)3受热分解成小薄片状Pr6O11。纳米粒状Pr6O11在900℃下保温10 min获得,其对可见光的吸收能力显著优于小薄片状Pr6O11。

The nano-granular Pr6O11 was prepared by thermal decomposition using Pr2(C2O4)3·6 H2O as the praseodymium source.The thermal decomposition process of Pr2(C2O4)3·6 H2O in air was studied by TG-DTA curves.The phases,morphologies and optical absorption properties of the thermal decomposition products of Pr2(C2O4)3·6 H2O in air were characterized by XRD,SEM and UV-Vis spectrophotometer,respectively.The results show that there are two main stages in the thermal decomposition process of Pr2(C2O4)3·6 H2O in air.The first stage is room temperature^300 ℃,and large flake-like Pr2(C2O4)3·6 H2O loses its adsorption water and crystal water to turn into small flake-like Pr2(C2O4)3.The second stage is 300~800 ℃,and small flake-like Pr2(C2O4)3 is thermally decomposed into small flaky Pr6O11.Nano-granular Pr6O11 is obtained by heat preservation at 900 ℃ for 10 min,and its absorption ability for visible light is significantly better than that of small flaky Pr6O11.