La_(0.4)Sr_(0.6)MnO_3纳米晶的制备及光催化性能  

Preparation of nano-crystalline La_(0.4)Sr_(0.6)MnO_3 and its photocatalytic performance

作　　者：韦超[1] 夏训峰[2] 王京刚[1] 王丽君[2] 张颖[2] 吕慧瑜[1] WEI Chao XIA Xunfeng WANG Jinggang WANG Lijun ZHANG Ying Lu Huiyu(College of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100010, China State Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution, Chinese Research Academy of Environmental Sciences, Beijing 100012, China)

机构地区：[1]北京化工大学化学工程学院,北京100010 [2]中国环境科学研究院国家环境保护地下水污染过程模拟与控制重点实验室,北京100012

出　　处：《环境工程技术学报》2017年第1期32-38,共7页Journal of Environmental Engineering Technology

基　　金：国家科技支撑计划项目(2014BAC02B02)

摘　　要：采用柠檬酸络合法,以金属硝酸盐和柠檬酸为原料,经过溶解、蒸发、干燥、煅烧、研磨等工艺制备La_(0.4)Sr_(0.6)MnO_3纳米晶催化剂,应用X射线衍射(XRD)、电子显微镜(SEM)、X射线光电子能谱(XPS)等技术表征其物化特性及微观结构。结果表明:制得的催化剂为立方晶相的纳米晶;形貌呈球形;分散性较好;各元素所占比例与化学式基本相符。以甲基橙(MO)为目标污染物探究La_(0.4)Sr_(0.6)MnO_3纳米晶在可见光下的光催化性能,通过改变试验因素(溶液的pH和氧化剂)来探究其光催化活性。结果表明:甲基橙在酸性条件(pH为1.4)下的降解效果比碱性条件好,La_(0.4)Sr_(0.6)MnO_3纳米晶对其的降解率可达75%以上;有氧化剂存在的条件下,La_(0.4)Sr_(0.6)MnO_3纳米晶对甲基橙的降解率更高;La_(0.4)Sr_(0.6)MnO_3纳米晶的吸附性能和光催化性能满足朗缪尔模型及一级反应动力学模型。Citric acid complexing method was adopted to prepare nano-crystalline La_（0.4）Sr_（0.6）MnO_3. The material was based on metal nitrate and citric acid,processed with dissolving,evaporation,drying,calcination and milling,etc. Techniques of XRD,SEM,and XPS were used to characterize its physical chemical properties and microscopic structure. The results showed that the catalyst was conformed to cubic phase perovskite,with spherical shape and good dispersity,and the proportion of each element met with the chemical formula basically. The photocatalytic performance of the nano-crystalline La_（0.4）Sr_（0.6）MnO_3 was explored with methyl orange（ MO） under visible light. The photocatalytic activity was investigated by changing the experimental factors,such as pH of solution and oxidant.The results showed that the degradation performance of MO under the acidic condition（ pH 1. 4） was better than the alkaline condition,and the degradation of MO could reach more than 75% under the acidic condition.Meanwhile,nano-crystalline La_（0.4）Sr_（0.6）MnO_3 with oxidant showed better photocatalytic activity than that without oxidant. The adsorption and photo-oxidation properties of nano-crystalline La_（0.4）Sr_（0.6）MnO_3 were explored,and the results met with the Langmuir model and first order reaction kinetics model.

关 键 词：La_(0.4)Sr_(0.6)MnO_3纳米晶 甲基橙(MO) 可见光 光催化 

分 类 号：X131[环境科学与工程—环境科学]