超细钙钛矿型PrMnO_3制备、表征及光催化

Preparation,Characterization and Photocatalysis of Ultrafine Perovskite PrMnO_3

以Pr6O11和Mn（NO3）2为主要原料,采用＂溶胶-凝胶＂法结合＂真空干燥＂技术制备超细钙钛矿型PrMnO3;用TG-DTA,TEM,XRD,FT-IR等手段进行表征;以紫外灯为光源,用超细PrMnO3光催化降解甲基橙溶液。结果显示：170℃真空干燥制得的Pr-Mn干凝胶为无定形的疏松土黄色粉末,由大量直径介于10~20 nm的球形小颗粒组成;Pr-Mn干凝胶热处理过程中,500℃时出现晶相Pr6O11,700℃时产生晶相Mn2O3,Pr影响了Pr-Mn干凝胶中Mn的晶化,900℃时得到粒径小于100 nm结晶度较好的纯晶相钙钛矿PrMnO3;以300 W紫外灯为光源,用0.50 g超细PrMnO3处理10 mg.L-1甲基橙溶液1000 ml,2 h即可完全降解,该降解过程属动力学一级反应。

With Pr6O11 and Mn（NO3）2 as raw materials,ultrafine perovskite PrMnO3 was prepared by sol-gel method and vacuum drying technology.The perovskite was characterized by TG-DTA,XRD,TEM,and FT-IR.The photocatalytic activity was tested by photocatalysis degrading methyl orange solution in the system of PrMnO3 suspension,irradiated under ultraviolet lamp.The results showed that at 170 ℃,the Pr-Mn xerogel was loose khaki powder with good dispersibility.The xerogel was made up of a mass of global grains with uniform size whose diameters were about 10~20 nm.In the process of thermal treating on Pr-Mn xerogel,the crystalline phase Pr6O11 and Mn2O3 appeared at 500 and 700 ℃,respectively;The crystallization process of manganese oxide was affected by Pr;After thermal treating at 900 ℃,the pure crystalling phase ultrafine perovskite PrMnO3 was prepared,and the particle size was smaller than 100 nm.Taking the 300 W UV lamp as the photo source,10 mg·L-1 methyl orange degradated by the superfine PrMnO3 powder,the degradation efficiency was 100% at the radiation time 2 h,this degeneration process was the dynamics first-level reaction.