Preparation and Electrochemical Characterization of Conical and Hemispherical Ultramicroelectrodes

摘要

We describe a new ultramicroelectrode fabrication technique which has allowed the preparation of conical and hemispherical platinum-iridium ultramicroelectrodes with radii of 0.5 micro m-10 micro m. These electrodes have been characterized by scanning electron microscopy, cyclic voltammetry and chronoamperometry. The smallest radii electrodes (r < 2 micro m) exhibited diffusional behavior in accord with a hemispherical geometry, while larger radii electrodes exhibited conical diffusion behavior. A first order mathematical approach to diffusion at conical surfaces has been developed to explain the results for these electrodes. Conical, Hemispherical ultramicroelectrodes, Construction, and Characterization. (mjm)