The long-time chronoamperometric current at an inlaid disk electrode

Existing analytical solutions for the long-time chronoamperometric current response at an inlaid disk electrode are restricted to diffusion-limited currents due to extreme polarisation or reversible kinetics at the electrode surface. In this article, we derive an approximate analytical solution for the long-time-dependent current when the kinetics of the redox reaction at the electrode surface are quasi-reversible and the diffusion coefficients of the oxidant and reductant are different. We also detail a novel method for calculating the steady-state current. We show that our new method encapsulates and extends the existing solutions, and agrees with numerically simulated currents.

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► Analytical expression for chronoamperometric current at an inlaid disk electrode.
► Valid for quasi-reversible redox reactions at long times.
► Allows for unequal diffusion coefficients for the oxidant and reductant.