10.22 : טכניקות וולטמטריות: וולטמטריה מחזורית

Cyclic voltammetry investigates the redox property of a chemical system via an electrochemical cell.

This cell comprises working, reference, and counter electrodes immersed in an electrolyte containing the analyte of interest.

A triangular potential waveform is applied to the working electrode, sweeping the potential between an initial value, a vertex potential, and back to the starting value.

The potential starts at an initial value where no redox reaction occurs and then sweeps across to a value where the analyte undergoes either reduction or oxidation at the working electrode surface.

The potential is then reversed and swept back to its initial value allowing the reverse reaction to occur.

The current measured from the redox reaction plotted against the potential yields a cyclic voltammogram with two distinct peaks: an anodic peak for oxidation and a cathodic peak for reduction.

The peak positions indicate the redox potentials, while the peak currents are proportional to the concentration of the analyte.