On a conductive substrate, a redox reaction
operates under kinetic control (i.e., it depends on the value of the forward rate constant
and the reverse rate constant
). Hence the flux of
feedback to the tip depends on the values of
In this Demonstration, you can choose the reverse (
) or the forward reaction (
) that occurs on the substrate. Then, you can manually fit the experimental data (red points) by the theoretical line (blue line) to find the reaction rate
. This reaction rate
can also be fitted by the Mathematica
built-in function FindFit
when you check the "fit" checkbox.
To find the standard rate constant
, you provide the potential applied to the substrate
and the standard potential
of the reaction on the substrate;
is found by the Butler–Volmer equation.
 C. G. Zoski, "Scanning Electrochemical Microscopy," Handbook of Electrochemistry
Elsevier, 2007 pp. 471–540.