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.