Cyclic voltammetry

Figure 1. Typical cyclic voltammogram where j_pc and j_pa show the peak cathodic and anodic current densities respectively for a reversible reaction with a 5 mM Fe redox couple reacting with a graphite electrode in 1M potassium nitrate solution. E_PA and E_PC denote the corresponding electrode potentials (vs. Ag/AgCl) of maximal reaction rates. For an ideal reversible (Nernstian) reaction the theoretical peak separation (E_PA - E_PC) is 57 mV.

In electrochemistry, cyclic voltammetry (CV) is a type of voltammetric measurement where the potential of the working electrode is ramped linearly versus time. Unlike in linear sweep voltammetry, after the set potential is reached in a CV experiment, the working electrode's potential is ramped in the opposite direction to return to the initial potential. These cycles in potential are repeated until the voltammetric trace reaches a cyclic steady state. The current at the working electrode is plotted versus the voltage at the working electrode to yield the cyclic voltammogram (see Figure 1). Cyclic voltammetry is generally used to study the electrochemical properties of an analyte in solution or of a molecule that is adsorbed onto the electrode and to quantify electrochemical surface area of catalysts in electrochemical cells.