Vibrating single probe and stationary bi-probes to measure local electrochemical impedance spectroscopy.
Résumé
The electrochemical impedance spectroscopy is widely used to investigate the electrode kinetics. This method is recognized as a powerful method to discriminate one reaction model to another and also to evaluate the reaction rate of elementary steps. However, when the electrode kinetics is markedly distributed from one-electrode site to another, such as the pitting corrosion on passive metal surface or a flawed organic coating, the classic electrochemical impedance spectroscopy that accounts for the overall current is no longer valid to evaluate local phenomena. The local electrochemical impedance spectroscopy, which is defined by the local potential and the local current density, is thus more adequate for such systems. This paper will describe how to measure both of them, and what kind of information that these local electrochemical spectroscopy measurements can supply.