Further investigation of the equivalence of staircase and linear scan voltammograms. II - Effects of electron transfer kinetics, Ohmic drop and double-layer charging

摘要

Abstract The optimal value of sampling parameter that guarantees the global equivalence of staircase and linear scan voltammograms plotted for electrochemical reactions involving soluble species is re-examined in this second article taking the electron transfer kinetics, the uncompensated resistance and the double-layer charging current into account. The discussion is based on the numerical solution of linear/nonlinear integral-equation-based models. The comparison of voltammetric and staircase voltammetric current data is carried out in terms of the mean squared deviation between voltammograms. Main results concern the dependence of the optimal sampling parameter on the potential step amplitude of staircase signal, and the dimensionless parameters pertaining to kinetic, Ohmic and capacitive effects. Highlights ? The optimal sampling condition for the SCV technique depends on reaction kinetics. ? The optimal sampling condition also depends on Ohmic drop and double-layer charging. ? Accurate evaluation of the Faradaic LSV current from SCV data is not a trivial task. ]]>