A new experimental approach to understanding microscopic details of the electrode/electrolyte interface

The article contributes to understanding the microscopic details of the electrochemical interphase and the electron transfer mechanism in a real experiment. The dynamic responses of the electrical phase interface were monitored via cyclic voltammetry of [Fe(CN)6]3-/4- on a pencil graphite electrode in an aqueous KCl solution, and the CV recordings were evaluated using elimination linear scan voltammetry (EVLS). The voltammetric data processing EVLS software, derived primarily for the reversible system, is capable of describing and distinguishing the diffusion, capacitance, and kinetic contributions of these current components. Based on the EVLS functions which eliminate the diffusion and charging current components or the diffusion and kinetic current components, we performed a detailed analysis of the state where the electronics meet the ionics. An emphasis was placed on the relationship between the dynamic response of the electric double layer and (a) the material of the graphite electrode, (b) the concentration of the [Fe(CN)6]3-/4-, (c) the concentration of the KCl, and (d) the presence or absence of oxygen in the solution. Our new approach to evaluating voltammetric data is characterized by experiments that promote understanding the electrochemical processes, influenced especially by changes in the electrical double layer. The results open a perspective of further research to facilitate a rational clarification and optimization of electrode processes.