Acta Phys. -Chim. Sin. ›› 2009, Vol. 25 ›› Issue (09): 1725-1730.doi: 10.3866/PKU.WHXB20090803

• ARTICLE • Previous Articles     Next Articles

Electrochemical Activity of IrO2 Electrodes in Aqueous Solutions Containing 4-Chlorophenol

WANG Xiao-Mei, HU Ji-Ming, ZHANG Jian-Qing, CAO Chu-Nan   

  1. Department of Chemistry, Zhejiang University, Hangzhou 310027, P. R. China|State Key Laboratory for Corrosion and Protection, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, P. R. China
  • Received:2009-03-30 Revised:2009-05-21 Published:2009-09-03
  • Contact: HU Ji-Ming E-mail:kejmhu@zju.edu.cn

Abstract:

The effect of 4-chlorophenol (4-CP) on the electrochemical activity of Ti-based IrO2 electrodes in acidic aqueous solutions was investigated within the electrochemical window for 4-CP. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) measurements both indicated that the existence of 4-CP in solution resulted in the activation of the IrO2 electrode in the electrochemical window. However, the testing results at metallic Ir electrode showed that the electrode activity was inhibited by 4-CP because of its adsorption onto the metal surface. A possible mechanismis proposed based on the influence of 4-CP on the electrochemical activities of these two electrode materials. The activation of IrO2 is believed to be related to its ease of transition from lower-valent to higher-valent oxides in the electrochemical window. The later oxides can be chemically oxidized and can remove organic molecules that are adsorbed onto the oxide electrode surface.

Key words: Electrochemical activity, IrO2 electrode, 4-Chlorophenol, Aqueous solution, Activation

MSC2000: 

  • O646.5