Magnetohydrodynamic transfer function applied to ultramicroelectrode systems

Abstract

The magnetohydrodynamic (MHD) transfer function (∂ I/∂ B), which has been successfully used in the investigation of various electrochemical systems, has also proved useful for the elucidation of reaction mechanisms involved in electrodeposition of metals. Yet, its use had been so far restricted to macroscopic electrodes. We propose here its application for ultramicroelectrodes (UMEs). In a recent work carried out in our laboratory with classical EIS techniques, we have demonstrated the reliability of the UMEs for the characterisation of the magneto-induced convective effect. We confirm this behaviour through the measurement of (∂ I/∂ B): at the limiting current, (∂ I/∂ B) shows an evolution in agreement with the previous stationary studies and the EIS investigations. In particular, the variation of the low frequency modulus confirms the relationship between the limiting current and the product B 1/3× C 4/3 insofar as the non-MHD convection has been taken into account.