chronamperometrie

Chronamperometry is a powerful electrochemical technique used to study the kinetics of electrode reactions. It involves applying a potential step to an electrode and then measuring the resulting current as a function of time. The applied potential is typically a step from an initial value, where no significant faradaic current flows, to a final value, where the reaction of interest is significantly activated.

The resulting current-time transient provides valuable information about the rate of the electrochemical process. Initially, the current is often diffusion-controlled, meaning it is limited by the rate at which reactants can reach the electrode surface. As time progresses, the concentration of reactants near the electrode surface decreases, and the current decays. The rate of this decay is directly related to the kinetics of the electron transfer reaction.

Analysis of the chronamperometric curve can yield parameters such as the heterogeneous rate constant, diffusion coefficients, and adsorption/desorption processes. By examining the shape and magnitude of the current decay, researchers can differentiate between fast and slow electrode reactions. This technique is widely applied in various fields, including electrocatalysis, corrosion studies, and the development of electrochemical sensors. It offers a direct way to probe the dynamic behavior of electrochemical systems.