Application of double pulse theory for hemispherical microelectrodes to the experimental study of slow charge transfer processes

Differential Pulse Voltammetry and Reverse Pulse Voltammetry are applied to the study of the electrode kinetics of slow charge transfer processes at hemispherical microelectrodes of ca. 25 μm radius. The electrochemical reversibility of three redox systems: 3-nitrophenolate−/2−, 3-nitrophthalate2−/3− and europium3+/2+, are evaluated with both techniques by determining the heterogeneous rate constant, the electron transfer coefficient as well as the formal potential for each.The experimental results show the value of these techniques for the characterization of the electrode kinetics by means of simple diagnostic criteria and single-point fit to general working curves. Further, theory developed for double potential pulse under radial diffusion conditions is validated.