物理化学学报 >> 2014, Vol. 30 >> Issue (12): 2263-2271.doi: 10.3866/PKU.WHXB201410141

电化学和新能源 上一篇    下一篇

功能化石墨烯/活性炭复合电极及不对称电容器脱盐

卢淼1, 刘建允1, 程健1, 王世平1, 杨健茂2   

  1. 1. 东华大学环境科学与工程学院, 国家环境保护纺织污染防治工程技术中心, 上海 201620;
    2. 东华大学分析测试中心, 上海 201620
  • 收稿日期:2014-06-23 修回日期:2014-10-10 发布日期:2014-11-27
  • 通讯作者: 刘建允 E-mail:jianyun.liu@dhu.edu.cn
  • 基金资助:

    国家自然科学基金(21476047, 21105009), 电分析国家重点实验室课题(SKLEAC201205)和中央高校基本科研业务费专项资金(2232012A3-05)资助

Functionalized Graphene/Activated Carbon Composite Electrodes for Asymmetric Capacitive Deionization

LU Miao1, LIU Jian-Yun1, CHENG Jian1, WANG Shi-Ping1, YANG Jian-Mao2   

  1. 1. State Enviromental Protection Engineering Center for Pollution Treament and Control in Textile Industry, School of Environmental Science and Engineering, Donghua University, Shanghai 201620, P. R. China;
    2. Analysis and Test Center, Donghua University, Shanghai 201620, P. R. China
  • Received:2014-06-23 Revised:2014-10-10 Published:2014-11-27
  • Contact: LIU Jian-Yun E-mail:jianyun.liu@dhu.edu.cn
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (21476047, 21105009), Foundation of State Key Laboratory of Electroanalytical Chemistry, China (SKLEAC201205), and Fundamental Research Funds for the Central Universities, China (2232012A3-05).

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摘要：

以3-氨丙基三乙氧基硅烷(AMPTS)修饰氧化石墨(GO)还原合成氨基功能化石墨烯(GP-NH2). 傅里叶变换红外(FTIR)光谱和X射线能谱(EDX)分析证明了氨基基团的成功接枝. 以GP-NH2为添加剂, 制备胺化石墨烯/活性炭(GP-NH2/AC)复合电极, 并以GP-NH2/AC 为正极, AC电极为对电极, 组装不对称电容器(AC||GPNH2/AC)用于电容脱盐. 实验表明, AC||GP-NH2/AC 单循环脱盐量为7.63 mg·g-1, 电流效率达77.6%. 利用磺酸重氮盐接枝石墨烯制备磺化石墨烯(GP-SO3H)及磺化石墨烯/活性炭(GP-SO3H/AC)复合电极. 并以GPSO3H/AC为负极, GP-NH2/AC 为正极, 组装不对称电容器(GP-SO3H /AC||GP-NH2/AC)用于电容脱盐, 其平均脱盐速率可达0.99 mg·g-1·min-1, 比纯AC电极提高了接近5倍. 充放电速率提高了30%; 而且由于正、负极表面固有电荷的存在, 大大降低了反离子效应, 电流效率由40% (纯AC||AC对称电容器)提高到92.8%. 表明电极内功能化导电石墨烯的存在既提高了导电性, 又兼具离子选择性的作用, 从而明显改善电极的脱盐性能.

关键词: 胺化石墨烯, 磺化石墨烯, 不对称电容器, 电容器脱盐

Abstract:

Aminated graphene (GP-NH2) was fabricated via the modification of graphite oxide (GO) with 3-aminopropyltriethoxysilane (AMPTS), and the covalent grafting of the amine functional groups was confirmed using Fourier transform infrared (FTIR) spectroscopy and energy-dispersive X-ray (EDX) spectroscopy. The aminated graphene (GP-NH2)/activated carbon (AC) composite electrode (GP-NH2/AC) was prepared, using the GP-NH2 as an additive. An AC||GP-NH2/AC asymmetric capacitor for capacitor deionization was then assembled using the GP-NH2/AC electrode as the positive electrode and AC as the negative electrode. A salt removal of 7.63 mg·g-1 was achieved using the AC||GP-NH2/AC capacitor, and current efficiency was increased to 77.6%. AGP-SO3H/AC electrode was then prepared by mixing AC with sulfonated GP. With GP-NH2/AC as the positive electrode, and GP-SO3H/AC as the negative electrode, a GP-SO3H/AC||GP-NH2/AC asymmetric capacitor was assembled for capacitive deionization. An average desalting rate of 0.99 mg·g-1·min-1 was achieved, almost five times higher than that achieved using an AC||AC symmetric capacitor. The chargedischarge rate showed a 30% increase. The existence of the intrinsic charge on the electrode surface greatly inhibited the migration of counter ions, so that the current efficiency was significantly enhanced (to 92.8%) in comparison with the value achieved using an AC||AC capacitor (40%). These results demonstrated that the functionalized graphene in the AC electrode not only enhanced the conductivity, but also controlled the selective adsorption of ions, thereby significantly improving the deionization performance.

Key words: Aminated graphene, Sulfonated graphene, Asymmetric capacitor, Capacitive deionization