Acta Phys. -Chim. Sin. ›› 2015, Vol. 31 ›› Issue (7): 1215-1218.doi: 10.3866/PKU.WHXB201506102

• COMMUNICATION • Previous Articles     Next Articles

Charge-Transfer Reactions at the Interface between Atmospheric- Pressure Microplasma Anode and Ionic Solution

REN Zhong-Hua, LU Yue-Xiang, YUAN Hang, WANG Zhe, YU Bo, CHEN Jing   

  1. Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084, P. R. China;Beijing Key Laboratory of Radioactive Waste Treatment, Tsinghua University, Beijing 100084, P. R. China
  • Received:2015-04-24 Revised:2015-06-10 Published:2015-07-08
  • Contact: LU Yue-Xiang E-mail:luyuexiang@mail.tsinghua.edu.cn
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (21390413, 21405090, 91426302), Program for Changjiang Scholars and Innovative Research Team in University, China (IRT13026), and Tsinghua University Initiative Scientific Research Program, China (2014z22063).

Abstract:

Atmospheric- pressure microplasma is an attractive gaseous electrode, and may replace the commonly used rare metal electrodes for electrochemical reactions. The reactions at the plasma anode-liquid interface have not been well investigated, and application of plasma anodes to electrodeposition is still rare. In this communication, by choosing the oxidation of ferrocyanide to ferricyanide as a model reaction, we carefully investigated the charge-transfer reaction at the interface between a plasma anode and an ionic solution. The results showed that ferrocyanide was progressively oxidated to ferricyanide over time, and the rate of oxidation was proportional to the discharge current. We also found that after the discharge the oxidation percent of ferrocyanide still increased approximately linearly with storage time, and the increasing rate was dependent on the discharge time. The rate of oxidation after discharge was much lower than that caused by discharge. These results demonstrate that atmospheric-pressure microplasma could act as a gaseous anode for transferring positive charges at the plasma-liquid interface and inducing electrochemical reactions in solution. During discharge, oxidative active species were also produced. We also successfully electrodeposited copper on stainless steel with the assistance of a microplasma anode in CuSO4 saturated solution, and the current efficiency was about 90%.

Key words: Microplasma, Anode, Charge transfer, Interface, Electrodeposition

MSC2000: 

  • O646.9