Applied Waveform and Data-Acquisition

The Pulse Voltammetry software implements a popular form of square-wave voltammetry generally called “Osteryoung” SWV. Another variant, known as “Barker” SWV involving a linear voltage-ramp, is less common, and not implemented in the software.

In a square-wave voltammetric experiment, a complex voltage sweep is applied to the working electrode in an electrochemical cell. This waveform can be constructed as a sequence of fixed height pulses (Curve A, below) added to a voltage staircase (Curve B, below). The resulting waveform is seen in the figure below.

The pulse height is generally 20 to 50 mV. The staircase has 2 to 10 mV steps. In the diagram above, notice that the square-wave and staircase waveforms are synchronized and that the square-wave has a 50% duty cycle.

The staircase waveform in the Pulse Voltammetry is defined to begin at Einitial and end at Efinal The duration of the sweep is defined by the staircase step-height (Estep), the square-wave frequency (f), and the initial and final potentials.

Sweep Time = (Efinal – Einitial) / (f × Estep)