chronoamperometri

Chronoamperometry is an electrochemical technique used to study the current response of an electrochemical system over time when a potential is applied. It is a type of potentiostatic control where the potential of the working electrode is stepped to a specific value and held constant. The resulting current flowing through the cell is then monitored as a function of time. This current is typically diffusion-controlled, meaning it is influenced by the rate at which electroactive species can reach the electrode surface.

The characteristic response in chronoamperometry often shows a sharp initial current followed by a decay. This decay is usually described by the Cottrell equation for diffusion-limited processes. The initial current is proportional to the concentration of the electroactive species and inversely proportional to the square root of time. By analyzing the shape and magnitude of the current-time curve, important information can be obtained about the kinetics of electron transfer reactions, diffusion coefficients of species, and concentrations of analytes.

Chronoamperometry is a versatile technique with applications in various fields, including analytical chemistry for quantitative analysis of substances, electrocatalysis for understanding reaction mechanisms, and materials science for studying surface processes. It is particularly useful for investigating fast electrochemical reactions and for determining diffusion coefficients of dissolved species. The simplicity of the experimental setup and data analysis makes it a widely accessible and valuable tool in electrochemistry.