Cottrell Equation for the Potential-Step Experiment

number of electrons

1

2

diffusion coefficient 

2

m

/s

1.×

-10

10

concentration (mM)

1

time (s)

0.05

The Cottrell equation in electrochemistry gives the current to a planar electrode in the potential-step experiment. This Demonstration shows the dependence of the current on the time, concentration, and diffusion coefficient.