Electrochemical characterization of the plasma-water interface
Abstract
Nonthermal atmospheric pressure plasmas generated using noble gases act as gaseous electrodes capable of promoting electrochemical reactions when in contact with aqueous media. Despite overwhelming evidence in favor of the interfacial region between the plasma and solution being a reducing environment, the plasma-liquid interface has not been evaluated from an electrochemical perspective. Herein, we present an electrochemical method to measure the overpotential at the plasma-liquid interface of solutions containing organic redox couples. Negative overpotentials indicate that the interfacial region is a reducing environment, which is consistent with the results of colorimetric assays using redox indicators. The reaction rates are related to the magnitude of the overpotential, as expected from electrochemical kinetic models. The ability to characterize the overpotential of plasma-liquid interfaces adds to the plasma electrochemistry toolkit and contributes to efforts being made to tune gaseous electrodes for the rational control of redox reactions.
- Publication:
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Journal of Physics D Applied Physics
- Pub Date:
- April 2020
- DOI:
- 10.1088/1361-6463/ab6e9c
- Bibcode:
- 2020JPhD...53p5202O
- Keywords:
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- atmospheric pressure plasma jet;
- plasma-liquid interactions;
- plasma electrochemistry