Application of a finite analytic numerical method .2. Digital simulation of charge transfer to an oblate hemispheroid microelectrode and experiment verification

The finite analytic numerical method combined with conformal mapping has been used to study the diffusion problems at an oblate hemispheroid microelectrode. The chronoamperometric and voltammetric responses for both reversible and quasi-reversible charge transfer at differently shaped oblate hemispheroid microelectrodes are simulated. The effect of the geometric parameter gamma = (b(0)/a(0)), dimensionless sweep rate parameter p = (nFva(0)(2)/RTD)(1/2), kinetic parameter Lambda = k(s)a(0)/D, on the current-potential-time responses is studied. The simulated results are compared with the results available in the literature and they are in good agreement. A mercury oblate hemispheroid microelectrode was fabricated and experiments were carried out in a chemically stable system, 2,3,5,6-tetrachlorobenzoquinone in acetonitrile. The experimental results also provide verification of digital simulations of the responses on the oblate hemispheroid microelectrode.