CNT/MnO2复合电极吸附去除水中Cd2+的研究  

Study on electrosorption of Cd2+ in aqueous solution with CNT/MnO2 composite electrodes

作　　者：施周[1] 王兴兴 卜嘉 靳兆琪 SHI Zhou;WANG Xing-xing;BU Jia;JIN Zhao-qi(College of Civil Engineering, Hunan University, Changsha 410082, China)

机构地区：[1]湖南大学土木工程学院

出　　处：《安全与环境学报》2018年第3期1089-1094,共6页Journal of Safety and Environment

基　　金：国家科技支撑计划项目(2012BAJ24B03)

摘　　要：为了探讨CNT/MnO2复合电极的电极特性及对Cd^2＋的电吸附性能、机理和影响因素,采用氧化还原法制备了碳纳米管负载二氧化锰（CNT/MnO2）材料,并涂覆在不锈钢网上制成复合电极;通过扫描电子显微镜技术、BET比表面积测试、循环伏安法、X射线光电子能谱仪和傅里叶变换红外光谱仪分别对该复合电极的表面形貌、比表面积、电化学性能、元素成分及所含官能团进行了表征。表征结果证实,复合电极材料的比表面积及比电容相比于CNT电极材料明显增大。进一步试验结果表明,复合电极对Cd^2＋的吸附量较CNT电极提高了6.125倍,且复合电极电吸附Cd^2＋的过程符合准二级动力学方程。The CNT/Mn O2composite electrode has been prepared through coating manganese dioxide on carbon nanotubes first,and then applying the CNT/MnO2composite on stainless steel cloth to make the electrode.The said electrode,including its surface structure,specific surface area,electrochemical properties,elemental composition and functional groups,was characterized accordingly by SEM,BET,cyclic voltammetry,XPS,and FTIR.The results show that the specific surface areas of the pure CNT and CNT/MnO2composite are 99.1 mg/g and 133.9 mg/g,respectively,whereas the much more specific surface area of the CNT/Mn O2 could be beneficial for its metal ions’adsorption.Further,electrosorption experiments with Cd^2＋on CNT/MnO2composite electrode have been done to evaluate a series of parameters effecting on the electrosorption,such as the ratio of CNT and MnO2,electrode voltage,initial solution p H,initial Cd^2＋concentration,flow rate and the electrode gap.The results indicate that the optimum ratio of CNT and Mn O2could be 1：4,and the adsorbed amount of Cd^2＋on the electrode tends to increase with the increase of the electrode voltage,p H（within the range from 3 to 7）,and the initial Cd^2＋concentration,and decrease with the increase of the electrode gap.Moreover,the adsorption creased by 6.13 times as that of CNT electrode when the initial Cd^2＋concentration was 60 mg/L.Besides,the electrosorption process has been examined with the pseudo-first-order and pseudo-second-order kinetic models,and it is found that the process of Cd^2＋on CNT/MnO2composite electrode tends to follow the pseudo-second-order model.Thus,according to the fact that the CNT/MnO2 composite electrode synthesized in this study exhibits high adsorption capacity for Cd^2＋ions,the CNT/Mn O2composite electrode could be expected to be a highly promising electrode for the real-world refractory environmental engineering need.

关 键 词：环境工程学:CNT/MnO2复合电极 电吸附 CD^2+ 

分 类 号：X703.1[环境科学与工程—环境工程]