物理化学学报 >> 2012, Vol. 28 >> Issue (03): 603603-608..doi: 10.3866/PKU.WHXB201112272

电化学和新能源 上一篇    下一篇

硫酸溶液中电化学改性石墨电极对Fe3+/Fe2+的电催化性能与准电容特性

孙亚萍1, 范新庄2, 芦永红1, 徐海波1   

  1. 1. 中国海洋大学化学化工学院, 海洋化学理论与工程技术教育部重点实验室, 山东青岛 266100;
    2. 中国科学院金属研究所, 沈阳 110016
  • 收稿日期:2011-11-07 修回日期:2011-12-19 发布日期:2012-02-23
  • 通讯作者: 徐海波 E-mail:xuwangri@163.com
  • 基金资助:

    山东省博士基金(BS2010NJ018, BS2011NJ019)和中央高校基础科研基金(201022006)资助项目

Electrocatalytic Performance and Pseudo-Capacitive Characteristics of Modified Graphite Electrode with Fe3+/Fe2+ in H2SO4 Solution

SUN Ya-Ping1, FAN Xin-Zhuang2, LU Yong-Hong1, XU Hai-Bo1   

  1. 1. Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100, Shandong Province, P. R. China;
    2. Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, P. R. China
  • Received:2011-11-07 Revised:2011-12-19 Published:2012-02-23
  • Contact: XU Hai-Bo E-mail:xuwangri@163.com
  • Supported by:

    The project was supported by the Doctor Foundation of Shandong Province, China (BS2010NJ018, BS2011NJ019) and Fundamental Research Funds for the Central Universities, China (201022006).

摘要: 通过循环伏安(CV)、恒电流充放电和电化学阻抗谱(EIS)等测试方法, 研究了电化学改性石墨电极对硫酸溶液中Fe3+/Fe2+的电催化性能与准电容特性. 结果表明: 由于电化学改性石墨电极表面存在大量的含氧活性官能团, 使其对Fe3+/Fe2+的氧化还原反应具有极高的电催化性能, 并具有可逆反应过程特征. 在含有0.5 mol·L-1 Fe3++0.5 mol·L-1 Fe2+的2.0 mol·L-1 H2SO4溶液中, 其表观面积比电容是不含铁离子硫酸溶液的1.808 倍,达到2.157 F·cm-2; 同时, 铁离子浓度的增大也能够进一步提高其电容量. Fe3+/Fe2+电对的加入增加了充放电时间, 有效提高了电化学电容器(EC)的电容存储容量和高功率特性. 电化学阻抗谱测试同样证实体系具有明显的电容特性. 因此, 可以利用电化学改性石墨电极表面的含氧活性官能团和溶液中Fe3+/Fe2+的氧化还原特性来共同储存和释放能量.

关键词: 电化学改性石墨电极, 铁离子, 电催化, 电化学电容, 准电容

Abstract: The electrocatalytic performance and pseudocapacitive characteristics of a modified graphite electrode (MGE) with Fe3+/Fe2+ in H2SO4 solution were studied by cyclic voltammetry (CV), constant current charge-discharge measurements, and electrochemical impedance spectroscopy (EIS). The results showed that the MGE had high electrocatalytic activity and good reversible characteristics for the redox reaction of Fe3+/Fe2+ because of a large quantity of oxygen-containing functional groups on the MGE surface. The apparent area-specific capacitance of the MGE in 2.0 mol·L-1 H2SO4 solution containing 0.5 mol·L-1 Fe3+ and 0.5 mol·L-1 Fe2+ reached 2.157 F·cm-2, which was almost double that in 2.0 mol·L-1 H2SO4 without Fe3+/ Fe2+ . Meanwhile, increasing the concentration of iron ions increased the capacitance of the MGE. The addition of Fe3+/Fe2+ made the charge-discharge curves more symmetric and change more slowly, which increases the charge-discharge time, and effectively improves the capacitive energy storage and high power performance for an electrochemical capacitor (EC). The obvious capacitive characteristics were confirmed by EIS, and are attributed to the oxygen-containing functional groups on the MGE and the Faraday redox reaction of Fe3+/Fe2+ in the thin electrolyte layer. Therefore, the oxygen-containing functional groups on the MGE surface and redox reaction of Fe3+/Fe2+ can be used together for energy storage and release.

Key words: Modified graphite electrode, Iron ion, Electrocatalysis, Electrochemical capacitor, Pseudo-capacitance

MSC2000: 

  • O646