Acta Phys. -Chim. Sin. ›› 2011, Vol. 27 ›› Issue (05): 1116-1121.doi: 10.3866/PKU.WHXB20110515

• ELECTROCHEMISTRY AND NEW ENERGY • Previous Articles     Next Articles

Redox Stability of Polypyrrole in Aqueous Electrolyte Solutions by a Recurrent Potential Pulse Technique

TIAN Ying1, WANG Jing-Ri2, LIU Ming1, SHI Kun1, YANG Feng-Lin3   

  1. 1. College of Environmental and Chemical Engineering, Dalian Jiaotong University, Dalian 116028, Liaoning Province, P. R. China;
    2. Dalian Shengshi Environmental Co. Ltd., Dalian 116600, Liaoning Province, P. R. China;
    3. Department of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, Liaoning Province, P. R. China
  • Received:2010-12-01 Revised:2011-03-07 Published:2011-04-28
  • Contact: TIAN Ying E-mail:greenhusk@126.com
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (51078050).

Abstract:

The recurrent potential pulse (RPP) technique is an alternative and effective technique for redox stability measurement. We investigated the electrochemical redox stability of polypyrrole (ppy) films doped with sodium p-toluenesulfonate by RPP technique in this study. The reduction charge (Qred) and the ratio of reduction and oxidation charges (Qred/Qox) obtained from the switching potentials in aqueous solutions of H2SO4, Na2SO4, and NaOH were calculated to describe the reversibility of ppy at the applied potential windows. We found that the irreversible overoxidation strongly depended on the pH value of the supporting electrolytes and on the switching potentials. The onset of the overoxidation potential is 0.8 V in H2SO4 solution while it is only 0.5 V in Na2SO4 solution. In NaOH solution, overoxidation occurs at any potential indicating that the existence of OH- ions is directly responsible for overoxidation.

Key words: Polypyrrole, Overoxidation, Redox stability, Recurrent potential pulse

MSC2000: 

  • O646