ABSTRACT
When one surveys the current state of electroanalytical research and the applications of electroanalysis, one concludes that solid electrodes in general and carbon in particular have joined mercury as widely used, practical electrode materials. Although solid electrodes are used in many applications in bioanalysis, analytical voltammetry, energy conversion, and electrosynthesis, their development has followed a complex path through many electrode materials, surface preparations, and experimental procedures. Historically, the dependence of analytically useful observables such as current and potential on sometimes poorly characterized interfacial phenomena often led to difficulties with solid electrode performance and reproducibility. The renewable surface of the dropping mercury electrode (DME) is the major reason for its reliability and popularity, despite its often serious limitations in potential range and its mechanical inconvenience. The headaches associated with surface irreproducibility on solid electrodes are countered by major advantages in electroanalysis and by large-scale industrial applications of high economic value. The mechanical stability, wide potential range, electrocatalytic activity, and versatility of solid electrodes make them more attractive than mercury for a variety of applications. Since solid electrodes began to be used in electroanalysis about forty years ago, analytical chemists have learned to control reproducibility and have devised a variety of surface treatments and derivatizations that enhance selectivity and sensitivity. In numerous cases, solid electrodes have permitted analytical and mechanistic applications that were not possible with mercury electrodes. The success in acquiring new chemical information combined with applications of major economic impact has provided much of the driving force for developing solid electrodes.
