Spectroelectrochemistry. Application of optically transparent minigrid electrodes under semiinfinite diffusion conditions

Abstract

Work supported by the Air Force Office of Scientific Research under Grant AFOSR-69-1625.

Analytical aspects of absorption spectroelectrochemistry at a platinum electrode—I Study of metal ions

“…Two types of electrodes are in common use, namely, (1) thin-film electrodes made by coating a transparent substrate with metals (platinum, gold, silver, mer cury) 4 -6 or doped oxides (tin oxide or indium oxide) 1 -9 and (2) minigrid electrodes usually made by etching rectangular holes in fine metal foils (usually gold). 10 The methods of monitoring the electroactive species at these electrodes are (1) normal transmission spectroscopy (NTS), where the absorbafice of a light beam passing at right angles through the electrode surface is monitored and (2) internal reflection spec troscopy (IRS). The basis of IRS is the fact that when a light-beam undergoes total internal reflection at a phase boundary, the light-beam actually penetrates the rarer medium.…”

“…2 • 1 5 NTS at minigrid OTEs is described by Murray et al 10 These spectroelectrochemical methods have also been used in conjunction with thin-layer cells. These are narrow cells (typically 10-2 mm) with a small electrolyte volume (a few µI) so electrolysis becomes exhaustive after a few hundred msec.…”

Development of carbon based optically transparent electrodes from pyrolyzed photoresist for the investigation of phenomena at electrified carbon - solution interfaces

“…Described as a conducting glass electrode (CGE) at the time, the application of transparent and conductive coatings quickly gained acceptance for the investigation of optically absorbing electroactive species and their intermediates and products. Kuwana and colleagues [34][35][36][37][38][39][40][41], as well as other research teams [42], continued the development of optically transparent electrodes not only with transparent coatings, but also with the use of minigrid electrodes [43][44][45], which consist of a fine mesh (i.e., microscreen) of metal.…”

“…Minigrid OTEs can have several potential advantages over thin film OTEs. The optical transmission of minigrid OTEs is dependent on the perforations of the grid, and not on the electrode material itself [45]. Minigrid electrodes possess the same characteristics as their bulk material, minimizing issues resulting from thin film preparation like island formation and the internal ohmic resistance due to the nucleation and growth mechanism of metal thin films [24,[46][47][48].…”

“…Spectroelectrochemical experiments utilize a variety of OTEs. While transparent oxide electrodes are widely used, researchers also take advantage of thin film and grid electrodes that are composed of metals including gold, platinum, nickel, and silver [24,45].…”