Investigation of ELectrochemical Behavior of Ferri/Ferrocyanide Redox on Carbon Paste Based Electrodes for Mercury (II) Electrochemical Sensor

Abstract

The electrochemical characterisation of the materials used to make sensors is mostly based on the cyclic voltametry method. Cyclic voltametry is an electrical method for the dynamic study of electrochemical systems. Through a reversible potential sweep, the material is studied in contact with the ferri/ferrocyanide. Ferri/Ferrocyanide is one of the most studied chemical compounds in electrochemistry and photo-electrochemistry because of its singular known and controlled reactivity. The appearance of voltamorams and mathematical expressions make it possible to collect the information necessary for understanding the reaction. An electrode material is considered active if it shows a reversible peak in contact with the redox marker in cyclic voltametry. The mechanism of the reaction is also assessed using the peak potential difference ΔEp. The nature of the mass transport is determined by the anodic and cathodic peak current ratio Ipa/Ipc. The aim of this work is to compare the electrochemical activity of the Feri/Ferrocyanide couple achieved with carbon paste-based electrodes for application to the electrochemical sensor. The study of the peak potential difference ΔEp showed that the composition of the electrode material influences the reaction mechanism at the interface. Material transport and electronic charge transfer are impacted by complex phenomena. By studying the electrical quantities potential difference ΔEp, formal standard potential E° and current ratio Ipa/Ipc, the electrochemical sensors developed can be optimised.