A Potential-step Chronoamperometric Study of Ion Transfer at the Water/Nitrobenzene Interface

Abstract

Abstract Potential-step chronoamperometry, cyclic voltammetry, and chronopotentiometry have been applied to the study of the transfer of the tetramethylammonium (TMA+) ion across the interface between a 0.1 mol dm−3 lithium chloride aqueous solution and a 0.1 mol dm−3 tetrabutylammonium tetraphenylborate nitrobenzene solution. An analysis of the current-time and current-potential curves obtained by means of potential-step chronoamperometry indicates that the transfer of the TMA+ ion across the water/nitrobenzene interface is a reversible diffusion-controlled process, which can be explained by the theory of the chronoamperometry of a reversible charge transfer at the electrode surface. The values of the diffusion coefficient of the TMA+ ion in the aqueous phase and of the reversible half-wave potential of the TMA+ ion transfer, as determined by means of potential-step chronoamperometry, agreed well with those determined by means of cyclic voltammetry and chronopotentiometry.