物理化学学报 >> 2011, Vol. 27 >> Issue (04): 887-892.doi: 10.3866/PKU.WHXB20110426

电化学和新能源 上一篇    下一篇

电化学改性石墨电极在不同溶液中的准电容及电催化性能

范新庄, 芦永红, 孔祥峰, 徐海波, 王佳   

  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
  • 收稿日期:2010-11-19 修回日期:2011-01-23 发布日期:2011-03-29
  • 通讯作者: 徐海波 E-mail:xuwangri@163.com
  • 基金资助:

    山东省博士基金(BS2010NJ018)和中国海洋大学专项基金(201022006)资助项目

Pseudo-Capacitive and Electrocatalytic Properties of Electrochemically Modified Graphite Electrode in Different Solutions

FAN Xin-Zhuang, LU Yong-Hong, KONG Xiang-Feng, XU Hai-Bo, WANG Jia   

  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
  • Received:2010-11-19 Revised:2011-01-23 Published:2011-03-29
  • Contact: XU Hai-Bo E-mail:xuwangri@163.com
  • Supported by:

    The project was supported by the Doctor Foundation of Shandong Province, China (BS2010NJ018) and Special Foundation of Ocean University of China (201022006).

摘要:

通过循环电流阶跃方法制备电化学改性石墨电极(MGE), 用循环伏安(CV)法评价了MGE在酸性和中性溶液中的准电容特性, 并研究了其在HCl和HNO3溶液中的电催化作用. 结果表明: 在酸性条件下, MGE在H2SO4溶液中具有佷好的准电容特性, 比电容高达1.730 F·cm-2; 在HCl溶液中也具有很好的准电容特性, 且MGE对析氯反应具有一定的电催化活性(起始析氯电位负移238 mV), 使其电位窗变窄; 在HNO3溶液中没有准电容特性, 而MGE对NO3-离子的还原反应具有极强的电催化能力. 当电介质由酸性变为中性时, 虽然其峰电流密度有所降低, 但电位窗大幅度增宽, 意味着MGE在中性体系中的能量密度比酸性体系会有较大的提高.

关键词: 石墨, 电化学改性, 准电容, 析氯, 硝酸还原

Abstract:

A graphite electrode (GE) was electrochemically modified by recurrent galvanic pulses. The pseudo-capacitive behavior in acidic and neutral solutions and the electrocatalytic property in HCl and HNO3 solutions of the modified graphite electrode (MGE) were evaluated by cyclic voltammetry (CV). We found that the MGE exhibited a considerable pseudo-capacitance (the specific capacitance was high up to 1.730 F·cm-2) in H2SO4 solution and excellent pseudo-capacitive behavior was obtained in HCl solution as well except for a narrow potential window. This was due to the excellent electrocatalytic activity of the MGE toward the chlorine evolution reaction (the onset potential of chlorine evolution was negatively shifted 238 mV). However, the MGE showed no pseudo-capacitive behavior in HNO3 solution but did show electrocatalytic activity toward the reduction of nitric acid. Compared with the pseudo-capacitive behavior in acidic solutions, the potential window of the MGE in neutral solution was substantially broadened and its energy density improved greatly eventually even though the corresponding peak current density decreased.

Key words: Graphite, Electrochemical modification, Pseudo-capacitance, Chlorine evolution, Reduction of nitric acid

MSC2000: 

  • O646