Time resolved study of electrode reactions using Fourier transform impedance spectroscopy: mutually correlated adsorption kinetics of Cu 2+ and ClO 4− on gold

Abstract

This work demonstrates the time resolved capability of Fourier transform electrochemical impedance spectroscopy (FT-EIS) for in situ kinetic studies of electrode reactions. The model system studied here is a gold electrode, employed as a substrate for dc voltage controlled deposition and stripping of copper in the presence of ClO 4 − ions in an aqueous electrolyte. Full Nyquist plots are collected through 1-s intervals during the occurrence of dc voltage controlled surface reactions. Distinctly different signatures of deposition and stripping of Cu are observed in the time resolved EIS data. Mutually coupled EIS features of ClO 4 − and Cu 2+ indicate how the two types of ions affect each other’s adsorption kinetics as functions of the applied dc voltage.