Membrane voltammetry: the metal/electrolyte interface

A straightforward method to generate ensembles of microelectrodes, using a commercial membrane material is reported. Quantitative analysis of the oxid ative currents flowing for a solution phase redox probe (in voltammetric an d chronoamperometric experiments) shows that a recessed microelectrode mode l describes transport to the individual elements of the ensemble. Treatment of the recessed electrode geometry in terms of an equivalent inlaid microe lectrode geometry is described. This approximation allows the voltage sweep rate dependence of the voltammetric currents and the standard electron tra nsfer rate constant of the redox probe to be obtained using existing theory . Furthermore, we propose that membrane voltammetry may be a useful tool fo r the characterisation of porous materials, given the inherent sensitivity of electrochemical experiments to mass transport parameters.