碳纳米管负载双金属复合材料对水中2,2',4,4'-四溴联苯醚的去除机制  

Removal mechanism of 2,2',4,4'-Tetrabromodiphenylether by carbon nanotubes supported bimetallic composites in water

作　　者：刘总堂[1,2] 谷成刚[1] 叶茂[1] 程吟文 生弘杰 卞永荣[1] 蒋新[1] 

机构地区：[1]土壤与农业可持续发展国家重点实验室,中国科学院南京土壤研究所,江苏南京210008 [2]中国科学院大学,北京100049

出　　处：《计算机与应用化学》2015年第4期449-454,共6页Computers and Applied Chemistry

基　　金：国家重点基础研究发展计划(973计划)(2014CB441105);国家自然科学基金项目(21377138;41401254和41271464);中国科学院南京土壤研究所知识创新工程领域前沿项目(ISSASIP1108/122011151432008);江苏省自然科学基金项目(BK2011886和BK20131463)

摘　　要：采用浸溃法制备了碳纳米管负载镍镧(Ni-La)/镍钴(Ni-Co)双金属复合材料Ni-La/CNT_s和Ni-Co/CNTs,采用投射电子显微镜(TEM)和X射线粉末衍射仪(XRD)对样品的结构特征和组成进行了表征。并通过吸附实验探讨了Ni-La/CNTs和Ni-Co/CNTs对水中2,2',4,4'.四溴联苯醚(BDE-47)的去除性能和去除机制。结果表明:Ni-La/CNTs和Ni-Co/CNTs表面负载了Ni-La或Ni-Co双金属粒子,主要是金属氧化物,并没有检测到明显的金属单质信号。Ni-La/CNTs和Ni-Co/CNTs对BDE-47均具有良好的去除性能;增大BDE-47的初始浓度,2种材料对BDE-47的吸附速率减小,而吸附量增大。准二级动力学方程能够较好的拟合BDE-47在Ni-La/CNTs和Ni-Co/CNTs上的吸附动力学过程,吸附速率常数大小顺序为:k_(CNTs)>K_(Ni-La/CNTs)>K_(Ni-Co/CNTs。CNTs对BDE-47的去除机制是吸附作用;而Ni-La/CNTs和Ni-Co/CNTs2种双金属复合材料对BDE.47的去除过程中,除了吸附作用占主要作用外,同时还存在一定的降解作用。Ni-La/CNTs和Ni-Co/CNTs重复使用4次后,对水中BDE-47的去除率仍超过80%,表明2种复合材料具有较好的重复使用性能。Nickel lanthanum/carbon nanotubes （Ni-La/CNTs） and nickel cobalt/carbon nanotubes （Ni-Co/CNTs） composites were prepared by impregnation method. The structure and composition of the Ni-La/CNTs and Ni-Co/CNTs were characterized by TEM and XRD. The removal mechanism of 2,2＇,4,4＇-tetrabromodiphenylether （BDE-47） by Ni-La/CNTs and Ni-Co/CNTs in water solution were also investigated. The results of TEM images indicated that the Ni-La or Ni-Co bimetallic nanopartieles were loaded onto the composites surfaces successfully with an average diameter in the range of （20~30） nm. The XRD results illustrated that the bimetallic nanoparticles were mainly Ni-La or Ni-Co oxides without demonstrable zero valent nickel, lanthanum and cobalt. Ni-La/CNTs and Ni-Co/CNTs had good removal performance for BDE-47 in water solution. When the initial concentration of BDE-47 increased to 1.0 mg.L1, the removal rates decreased and the adsorption capacities increased. The possible reason was that the active sites of Ni-LalCNTs and Ni-Co/CNTs were limited and the sorption processes needed more time to reach equilibrium at higher initial BDE-47 concentration. The removal processes of BDE-47 onto Ni-La/CNTs and Ni-Co/CNTs could be fitted by the pseudo-second order kinetic model perfectly, the adsorption rate order was kCNTs〉 kNi-La/CNTs〉 KNi-Co/cNrs. Predominant adsorption and weak degradation were coexisted in the removal process of BDE-47 by Ni-La/CNTs and Ni-Co/CNTs while there was only adsorption onto CNTs. In addition, the Ni-La/CNTs and Ni-Co/CNTs composites had good regeneration performance and the removal rates were still more than 80 % after four regeneration cycles.

关 键 词：碳纳米管 双金属复合材料:2 2’ 4 4’-四溴联苯醚 去除机制 

分 类 号：O647.3[理学—物理化学]