Effect of Oxygen-Containing Groups on Electrochemical and Marine Electric Field Response Properties of Carbon Fiber Electrode

Electric field response of carbon fiber sensor in sea water can be tuned up through modification of molecules or groups on its surface, which plays an important role in its high sensitivity and stability. Herein, high performance carbon fiber electrodes with different oxygen-containing functional groups were prepared by electrochemical oxidation coupled with electrochemical reduction, and their electric field response and electrochemical performances of electrodes are investigated. The results show that the electrochemical oxidation and reduction obviously alter the dominant contents of carbonyl, hydroxyl and carboxyl groups. Among them, carbonyl group has positive effects for paired carbon fiber electrode on its electrode potential stability and its distortion rate of electric field response curves, hydroxyl group makes the paired carbon fiber electrode more sensitive to weak electric field. Carboxyl group has negative effects on the electrode potential stability due to its high activity, but its larger specific capacitance and smaller charge transfer resistance are simultaneously obtained. The detailed relationship between the dominant oxygen-containing carbon fiber electrode and its electric field response is first reported systematically, and it will shed some light on the design of fast-stable and highly sensitive marine electric field electrodes.

Automated summary

The electric field response of carbon fiber sensors in sea water can be adjusted by modifying the molecules or groups on their surface. In this study, high performance carbon fiber electrodes with different oxygen-containing functional groups were prepared and their electric field response and electrochemical performances were investigated. The results showed that the oxidation and reduction processes altered the dominant contents of carbonyl, hydroxyl, and carboxyl groups, leading to different effects on the electrode potential stability, distortion rate of electric field response curves, sensitivity to weak electric fields, specific capacitance, and charge transfer resistance.