摘要
用均匀沉淀法、溶胶-凝胶相转移法和溶胶-凝胶蒸发干燥法制备了纳米氧化铁，研究了制备条件，并对产品进行了表征。扫描电镜和X射线衍射分析结果表明，以上3种方法制备的氧化铁，颗粒均在100-300nm之间。用溶胶-凝胶蒸发干燥法制备的样品C和样品D具备典型α型Fe2O3的物相特征。吸附实验表明，合成的纳米氧化铁对砷（V）均有较强的吸附性能，在初始砷质量浓度为2mg／L，pH值在4．0-6．0的范围内，能使溶液中的砷含量降到0．01mg／L以下，且吸附速度快，平衡时间短。溶胶-凝胶蒸发干燥法制备的纳米氧化铁在pH值为3．0、7．0和10．0时的最大砷吸附容量分别为30．96、30．58和17．06mg／g，与其他纳米氧化物相比，用此方法制备的纳米氧化铁对As（v）有较大的吸附能力，较普通块体氧化铁的吸附除砷性能更优。其吸附等温线能用Langmuir方程进行拟合，确定系数R^2〉0．95。
Nanometer-size iron oxides were respectively prepared by homogeneous precipitation, sol-gel phase transfer, and sol-gel evaporation processes, and the preparation conditions were studied and the powders were characterized. Scanning electron microscopy showed that the average grain size was between 100-300 nm. The adsorption of As（ V ） on the nanometer-size iron oxides prepared by the different processes under different conditions was compared experimentally. The results indicated that the nanometer-size iron oxides can lower the arsenic concentration to below 0.01 mg/L from 2 mg/L in solution at pH between 4. 0 and 6. 0. The maximal adsorption capacity of the iron oxides prepared by sol-gel evaporation process was 30.96, 30. 58 and 17.06 mg/g when the pH was 3, 7, and 10, respectively, and the adsorption capacity of the nanometer-size iron oxide thus prepared was greater than that of the other nanometer-size oxides and common block iron oxides. Its adsorption isotherm can be fitted by Langmuir adsorption equation with a correlation coefficient R^2 of 〉0. 95.
出处
《应用化学》
CAS
CSCD
北大核心
2007年第12期1418-1423,共6页
Chinese Journal of Applied Chemistry
基金
国家自然科学基金资助项目(40773059)
上海市重点基础研究计划(06JC14067)资助项目
广西科学基金(桂林自0728222)
广西"新世纪十百千人才工程"专项资金资助项目(2004217)
关键词
纳米氧化铁
制备
砷(V)
吸附
nanometer-size iron oxide, preparation, arsenic, adsorption
