LaCo0.5Cu0.5O3型钙钛矿活化过一硫酸盐降解AO7

Degradation of azo dye AO7 with peroxymonosulfate catalyzed by LaCo0.5Cu0.5O3 perovskite

采用溶胶-凝胶法制备LaCo1-xMxO3(M=Cu、Fe、Mn)型钙钛矿并用来活化过一硫酸盐(PMS)降解偶氮染料AO7.选取效果最好的LaCo 0.5Cu 0.5O 3型钙钛矿为研究对象,考察了钙钛矿投加量、PMS浓度、pH和染料废水中常见Cl-对LaCo0.5Cu 0.5O 3/PMS体系降解AO7的影响,分析了体系的反应过程并考察了矿化能力.结果表明,LaCo 0.5Cu 0.5O 3可以有效活化PMS降解AO7,反应随着材料投加量和PMS浓度的增加而加快.在中性条件下反应速度最快,过酸过碱均会抑制反应的进行.在优化条件为LaCo 0.5Cu 0.5O 3投加量20mg/L、PMS浓度0.50mmol/L、AO7浓度0.05mmol/L时,AO7可在20min内完全降解.该反应主要发生在材料表面并且主要活性物种为OH,对AO7具有优异的脱色能力和较好的矿化效果.

LaCo1-xMxO3(M=Cu、Fe、Mn)perovskite was prepared by sol-gel method,and then used to activate peroxymonosulfate(PMS)to decolorize azo dye orange 7(AO7).LaCo0.5Cu0.5O3 perovskite was found to show the best catalytic effect on PMS-activation for AO7 decolorization.The effects of LaCo0.5Cu0.5O3 dosage,PMS concentration,pH value and common ions(e.g.,Cl)in dye wastewater were further evaluated on the degradation of AO7 in LaCo0.5Cu0.5O3/PMS system.Results show that the degradation of AO7 was accelerated with the increase of LaCo0.5Cu0.5O3 dosage and PMS concentration.Neutral pH was most favorable for the degradation of AO7,and the degradation of AO7 was inhibited under acidic or alkaline conditions.AO7 can be completely degraded in 20min at the optimal operating conditions of 20mg/L LaCo0.5Cu0.5O3,0.50mmol/L PMS and 0.05mmol/L AO7.The reaction mainly occurred on the surface of the catalyst and OH was the main active species responsible for AO7 degradation.Overall,LaCo0.5Cu0.5O3 exhibits excellent performance on PMS activation to decolorize and mineralize AO7.