Cyclic voltammogram:

A cyclic voltammogram is obtained by measuring the current at the working electrode during the potential scan. A current could be considered the response signal to the potential excitation signal. A voltammogram is a show of current (vertical axis) versus potential (horizontal axis). Because the potential varies linearly along with time, the horizontal axis could also be thought of as a time axis. This will be helpful in understanding the basic principle of the technique.

A typical cyclic voltammogram is given in Figure. In a platinum working electrode is a solution containing 6.0 mm of K₃Fe (CN)₆ as the electroactive species in 1.0 M KNO₃ in water as the supporting electrolyte. A potential excitation signal used to

 Obtain this voltammogram is shown in Figure but with the negative switching potential of -0.15V. Thus, the vertical axis in Figure is now the horizontal axis of Figure. The initial potential (Ei) of 0.80 V applied at (a) is chosen to avoid any electrolysis of [Fe(CN)₆]^3-  when the electrode is switched on. A potential is then scanned negatively, forward scan, as denoted through the arrow. While the potential is sufficiently negative to reduce [FeIII(CN)₆]^3-  cathodic current is indicated by (b) due to electrode process

[Fe^III (CN₆)^3- + e → [Fe^II (CN)₆]^4-