高等学校化学学报 ›› 2017, Vol. 38 ›› Issue (1): 63.doi: 10.7503/cjcu20160658

• 物理化学 • 上一篇    下一篇

改性氧化石墨烯去除重金属离子的分子动力学模拟

刘沙沙1,2, 张恒1, 王华2, 苑世领1(), 侯士峰2()   

  1. 1. 山东大学化学与化工学院, 济南 250100
    2. 山东大学国家胶体材料工程技术研究中心, 济南 250100
  • 收稿日期:2016-09-21 出版日期:2017-01-10 发布日期:2016-12-05
  • 作者简介:联系人简介: 苑世领, 男, 博士, 教授, 主要从事分子模拟及其应用研究. E-mail: shilingyuan@sdu.edu.cn; 侯士峰, 男, 博士, 教授, 主要从事石墨烯材料研究. E-mail: shifenghou@sdu.edu.cn
  • 基金资助:
    国家自然科学基金(批准号: 21475076)和科技部国际合作专项基金(批准号: 2015DFA50060)资助.

Molecular Dynamics Simulations of EDTA-modified Graphene Oxide for Pb(Ⅱ) and Na(Ⅰ) Removal

LIU Shasha1,2, ZHANG Heng1, WANG Hua2, YUAN Shiling1,*(), HOU Shifeng2,*()   

  1. 1. School of Chemistry and Chemical Engineering
    2. National Engineering Research Center for Colloidal Materials, Shandong University, Jinan 250100, China
  • Received:2016-09-21 Online:2017-01-10 Published:2016-12-05
  • Contact: YUAN Shiling,HOU Shifeng E-mail:shilingyuan@sdu.edu.cn;shifenghou@sdu.edu.cn
  • Supported by:
    † Supported by the National Natural Science Foundation of China(No.21475076) and the International Special Project of the Ministry of Science and Technology, China(No.2015DFA50060).

摘要:

通过硅烷化反应在氧化石墨烯(Graphene oxide, GO) 表面嫁接螯合官能团N-(三甲氧基硅丙烷)乙二胺三酸(EDTA-Si), 得到改性氧化石墨烯(GO-EDTA), 采用分子动力学模拟在分子水平上研究了Pb2+在GO-EDTA 表面的动态吸附分布、 构象及动力学性质, 比较了Pb2+和单价Na+离子在氧化石墨烯上的吸附行为, 模拟了GO-EDTA与Ca2+相互作用, 与Pb2+的吸附行为进行了对比. 模拟结果表明, Pb2+和Na+的吸附位点是GO-EDTA 体系中的羧基, 而非氧化石墨烯表面的羟基; Pb2+和 Na+ 与羧基的吸附构象不同, 前者吸附构象以摩尔比2:1为主, 即两个羧基对一个Pb2+离子, 而后者更多倾向于摩尔比1:1的吸附模式, 即一个羧基对一个Na+离子; Pb2+离子相对于Ca2+和Na+离子, 形成的COO--Pb2+离子对构象越过的能垒最低, 但是破坏该离子对构象时能垒较高, 表明Pb2+离子在氧化石墨烯膜上表现出良好的吸附性.

关键词: 氧化石墨烯, 重金属, 吸附性能, 分子动力学

Abstract:

The chelating groups N-(trimethoxysilylpropyl) ethylenediamine triacetic acid(EDTA-silane) were linked to graphene oxide(GO) surfaces through a silanization reaction, and this modified GO(GO-EDTA) was used to remove the heavy metal in the solution. By using molecular dynamics simulation at the molecular level, the absorption distribution, dynamic properties of Pb2+ on the GO-EDTA surface were investigated, the different absorption behaviors of Pb2+ and Na+ between GO and GO-EDTA systems were compared. At the same time, the interaction between GO-EDTA and Ca2+ was simulated, which was comparable to the adsorption behavior of Pb2+. The simulation result shows that: (1) the adsorption sites of Pb2+ and Na+ are the carboxyl groups in the GO-EDTA system, rather than the hydroxyl groups on graphene oxide surface; (2) the absorption conformations of Pb2+ and Na+ to carboxyl groups are different. For Pb2+ ions, they form the 2:1 type with carboxyl group, i.e. one Pb2+ ion combines with two carboxyl groups; while for Na+ ions, it is the 1:1 type, i.e. one Na+ ion combines with one carboxyl group; (3) comparison with Ca2+ and Na+ ion, the energy barrier of forming COO--Pb2+ ion pair conformation is lowest while the energy barrier to break this conformation is higher. This result indicates that the Pb2+ ions are adsorbed well on GO and GO-EDTA films.

Key words: Graphene oxide, Heavy metal, Adsorption capacity, Molecular dynamic

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