【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_0.4Sr_0.6MnO₃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_0.4Sr_0.6MnO₃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_0.4Sr_0.6MnO₃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_0.4Sr_0.6MnO₃纳米晶对甲基橙的降解率更高;La_0.4Sr_0.6MnO₃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。更多还原

【Abstract】 Citric acid complexing method was adopted to prepare nano-crystalline La_0.4Sr_0.6MnO₃. 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_0.4Sr_0.6MnO₃ 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_0.4Sr_0.6MnO₃ with oxidant showed better photocatalytic activity than that without oxidant. The adsorption and photo-oxidation properties of nano-crystalline La_0.4Sr_0.6MnO₃ were explored,and the results met with the Langmuir model and first order reaction kinetics model.更多还原