A potential working electrode based on graphite and montmorillonite for electrochemical applications in both aqueous and molten salt electrolytes

Abstract

Abstract The feasibility of a novel graphite–MMT composite electrode for electrochemical processes in aqueous and molten salt electrolytes has been investigated. The graphite–MMT composite electrodes (G-MMTCEs) were fabricated by preparing composites in deionized water, pressing the dry composite under 1.03\u202f×\u202f104\u202fN ram force to obtain cylindrical electrodes (5.00\u202fcm long and 1.00\u202fcm in diameter) and firing the electrodes at around 550\u202f°C for 1\u202fh. The results indicate that the G-MMTCE containing 80% graphite showed the lowest resistivity (8.17\u202f×\u202f10−4\u202fΩm) and highest flexural strength (5.81\u202f×\u202f106\u202fNm2). The exponential decrease in resistivity from low to high graphite percentage is clearly observed for a series of G-MMTCEs. The lamella-like graphite structure held together by tiny clay particles accounts for the enhanced electrical and mechanical stability of the G-MMTCEs. It is also found that the fabricated G-MMTCE is very stable in molten salts as well as in aqueous electrolytes with different pH values. The G-MMTCE has advantages as a working electrode over a glassy carbon electrode (GCE) in analyte detection as well as in electropolymerization. A narrow working potential range and enhanced sensitivity are the major advantages of the G-MMTCE over the GCE under identical cell and measurement conditions.