# Concentration Profiles in Electrochemical Impedance Spectroscopy (EIS)

Concentration Profiles in Electrochemical Impedance Spectroscopy (EIS)

This Demonstration models the time dependence of the concentration profile for the soluble species involved in a reversible electron transfer reaction , taking place at the surface of a planar macroelectrode. The electrode potential is treated as a sinusoidal perturbation. The model assumes finite diffusion in the electrolyte, with a permeable or impermeable boundary condition at the distance from the electrode surface (the so-called finite-length diffusion or restricted diffusion), respectively. You can experiment with the effects of the amplitude of sinusoidal perturbation, the decimal logarithm of its frequency and the time variable, using the controls for the dimensionless parameters , and , respectively.

O

O+e⇌R

δ

δξ

logu

τ