Cyclic voltammetry excitation signal

Fig. 5 Linear sweep and cyclic voltammetry (a) dotted lines five profiles respectively at various typical excitation signal (b) current response times, increasing time shown by arrows] for a and concentration profiles [(c) forward scan cyclic voltammetric experiment.

Depending on the time variation of the applied potential, several types of voltammetry can be distinguished. Among them, the most widely used are linear and cyclic voltammetries. Here, the excitation signal is a linear potential scan that is swept between two extreme values, and in cyclic voltammetry the potential is swept up and down between the two values (or switching potentials) with the same absolute scan rate (v, usually expressed in mV/s), although it has the opposite sign [79]. 

Figure 3.21 Typical potential-time excitation signal for cyclic voltammetry.

Current step— The excitation signal used in controlled current techniques in which the potential is measured at a designated time [i]. See also - chronopotentiometry, -> cyclic chronopotentiometry, - staircase voltammetry. Ref. [i] Heineman WR, Kissinger PT (1984) In Kissinger PT, Heine-man WR (eds) Laboratory techniques in electroanalytical chemistry. Marcel Dekker, New York, pp 129-142... 

The types of voltammetry that u.se the various excitation signals are also listed in Figure 23-1. The first three of these techniques in parts a-c of Figure 23-1 are discussed in detail in the sections that follow. Cyclic voltammetry has found considerable application as a diagnostic tool that provides information about the mechanisms of oxidation/reduction reactions under various conditions. Cyclic voltammetry is discussed in Section 23D. 

In linear potential scan (LSV) and cyclic (CV) voltammetries, a potential varying linearly with time is applied between an initial potential, usually at a value where no faradaic processes occur, and a final potential (LSV) or cycled between two extreme (or switching) potential values at a given potential scan rate v (usually expressed in mV/sec). In other techniques, such as normal and differential pulse voltammetries (NPV and DPV, respectively), or square-wave voltammetry (SQWV), the excitation signal incorporates potential pulses to a linear or staircase potential/time variation. 

Excitation signals for potential scan voltammetries (a) linear sweep voltammetry (b-d) cyclic voltammetry (CV). 

A Excitation Signals in Voltammetry 717 25B Voltammetric Instrumentation 718 25C Hydrodynamic Voltammetry 723 25D Cyclic Voltammetry 737... 

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