物理化学学报 >> 2012, Vol. 28 >> Issue (05): 1269-1274.doi: 10.3866/PKU.WHXB201202242

材料物理化学 上一篇    

电化学间接测量法研究谷胱甘肽在多壁碳纳米管和活性炭上的吸附

汤儆, 曾峤, 陈振东, 黄向前   

  1. 福州大学化学化工学院, 教育部食品安全和分析检测重点实验室, 福州 350108
  • 收稿日期:2011-11-28 修回日期:2012-02-08 发布日期:2012-04-26
  • 通讯作者: 汤儆 E-mail:jingtang@fzu.edu.cn
  • 基金资助:

    国家自然科学基金(21073038, 21173048)资助项目

Electrochemical Indirect Measurement for the Study of Glutathione Adsorption on Multiwalled Carbon Nanotubes and Activated Carbon

TANG Jing, ZENG Qiao, CHEN Zhen-Dong, HUANG Xiang-Qian   

  1. Key Laboratory of Analysis and Detection Technology for Food Safety, Ministry of Education, College of Chemistry and Chemical Engineering, Fuzhou University, Fuzhou 350108, P. R. China
  • Received:2011-11-28 Revised:2012-02-08 Published:2012-04-26
  • Contact: TANG Jing E-mail:jingtang@fzu.edu.cn
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (21073038, 21173048).

摘要: 选取谷胱甘肽(GSH)作为小分子代表物, 利用Cr(VI)与GSH的相互作用, 即K2Cr2O7/H2SO4溶液加入GSH前后Cr(VI)还原峰电流值的差异, 通过差分脉冲伏安法(DPV)的测定, 可以间接测出GSH的含量. 尝试将这种电化学间接测量法应用于研究多壁碳纳米管(MWCNTs)与商业活性炭(AC)对GSH的吸附行为. 利用该方法可以确立GSH在二者的吸附量(Q)与吸附平衡浓度(Ce)的关系, 绘制吸附等温曲线. 根据Langmuir 方程和Freundlich 方程的拟合分析, 证明了与商业活性炭相比, GSH在MWCNTs 上的吸附更倾向Freundlich 模型, 即多分子层吸附. 利用扫描电子显微镜(SEM)和透射电子显微镜(TEM)进行形貌表征, 发现MWCNTs 具有发达的堆积孔结构, 有利于GSH小分子内扩散和吸附, 与实验结果一致.

关键词: 电化学间接测量法, 谷胱甘肽, 多壁碳纳米管, 活性炭, 吸附机理

Abstract: Because of the chemical reaction between Cr(VI) ions and glutathione, the peak reduction current of Cr(VI) ions decreases while adding glutathione (GSH) into a K2Cr2O7/H2SO4 solution. Thus the concentration of GSH can be detected indirectly by differential pulse voltammetry (DPV) analysis. This electrochemical indirect method was used to study the adsorption of GSH on multi-walled carbon nanotubes (MWCNTs) and activated carbon (AC), and can be used to determine the equilibrium relationship between GSH adsorption and its concentration. Unlike the result obtained from the active carbon, GSH adsorption on MWCNTs agrees better with that predicted by the Freundlich equation compared to that predicted by the Langmuir equation. The morphologies of MWCNTs and activated carbon were observed with scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The abundance of aggregated pores in MWCNTs is beneficial for the diffusion and adsorption of small GSH molecules, suggesting that MWCNTs could be developed as an adsorbent for small molecular substances.

Key words: Electrochemical indirect measurement, Glutathione, MWCNTs, Activated carbon, Adsorption mechanism

MSC2000: 

  • O643