CHEMICAL AND ELECTROCHEMICAL PROPERTIES OF LI+-IMPLANTED AND K+-IMPLANTED GLASSY CARBONS

Effects of ion implantation on chemical and electrochemical properties of glassy carbon (GC) were investigated. Ion implantations of Li+ and K+ with an acceleration energy of 150 keV were carried out in order to elucidate the chemical stability of the chemically-active elements, Li and K, doped in the chemically-stable substrate. The Li+- (or K+-) implanted GC surface layer was chemically and electrochemically stable in aqueous electrolytic solutions. Structure change, amorphization, induced by the ion implantation was observed by Raman spectroscopy. Concentration-depth profiles of Li and K in GC were measured by SIMS, which showed unusual distributions. Electrode characteristics of the ion-implanted GC electrodes were studied by cyclic voltammetry. Low residual current and high overpotentials of oxygen and hydrogen evolution reactions were obtained for the ion-implanted electrodes as advantages for a voltammetric sensing electrode, whereas low reversibility for a redox reaction (Fe(III) + e- ⇌ Fe(II)) was observed as a disadvantage. © 1990.