Ring-disc electrodes: Part 3. - Current-voltage curves at the ring electrode with simultaneous currents at the disc electrode

For reversible electrochemical systems, complete current-voltage curves are calculated for the ring electrode of a ring-disc system; the equations derived include the effect of passing current through the disc. The equations are obtained by the rigorous application of the proper boundary conditions to the convective diffusion equation. Despite the fact that the surface concentrations on the ring electrode vary with the radius, the results agree with those that would be obtained by the approximate Nernst diffusion layer treatment. The equations are tested for the Ag/Ag⁺ system and are found to be in good agreement with experiment.