Cyclic voltammetry
The graphs on this page are plotted using polarographic conventions where potentials become more negative along the (positive) x-axis and reduction currents are defined as positive. Equally common is the IUPAC convention where potentials become more positive along the (positive) x-axis and oxidation currents are defined as positive. For both conventions applying a more negative voltage is a reduction and the observed peak when scanning negative is a reduction current; applying a more positive voltage is an oxidation and the observed peak when scanning positive is an oxidation current. In practice the difference is a 180° rotation of the graph with a change in sign of the y-axis.
What is the shape of a cyclic voltammogram?
Scanning from +0.2 to -0.5 to +0.2 volts at 100 mV/sec shows a reduction and then an oxidation peak for a 0.001 M sample with E0 = -0.200 volts. The movie shows the scan taking place in real time.

How are cyclic voltammograms affected by E0?
E0 = -50, -75, -100, -125, -150, -175, -200, -225, -250, -275, -300, -325, -350 mV.

How are cyclic voltammograms affected by concentration?
Concentration = 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 mM

How are redox equilibria affected by scan rate?
Scan rate = 5, 10, 20, 50, 100, 200, 500, 1000 mV/sec.
A = 0.1 cm2 electrode, D = 10-5 cm2/sec diffusion, ks = 104 cm/s electron transfer rate

What if there are two reductions?
E0 = 300, 250, 200, 150, 100, 50, 0 mV.

G. Lisensky