Square wave electrolysis. I. The cyclic potential‐step method

Abstract

Drawbacks of the well-known potential-step method are briefly mentioned. A new method called the cyclic potential-step method is introduced, the essential of which is that a square wave voltage is applied to a polarisable electrode. It is shown mathematically that the current response approaches rapidly to a constant pattern. The derivations presented are free from restrictions concerning the reversibility of the system and the magnitude of the amplitude of the square wave.It is shown that the cyclic potential-step method offers easy means for the determination of the transfer-coefficient (a) and the standard exchange current density ( loo).

Electrochemical Faradaic Spectroscopy

“…In the present communication we address the question whether a form of a simple chronoamperometric experiment is possible, which provides analogous information from the electrode kinetics point of view as SWV. The roots of the present idea are found in the early work of Smit and Wijnen, in the methodology known as cyclic potential‐step method. Therefore, we analyse the behaviour of a common electrode mechanism under conditions of a pulse‐form chronoamperometric experiment, the excitation signal being obtained by combining a constant potential with a short‐duration small potential pulses, as in SWV (Figure A).…”

Square‐wave Voltammetry and Electrochemical Faradaic Spectroscopy of a Reversible Electrode Reaction: Determination of the Concentration Fraction of the Redox Couple

“…The net current component is virtually constant after the 15 th potential cycle ( p >15), being independent of the concentration parameter x (Ox). The apparent steady‐state characteristic is the most striking feature of the technique, implying promising application in electroanalysis [20]. For E sw =50 mV, n =1, and p >15, the dimensionless net current equals 0.742.…”

“…Figure 1), in order to test the performances of the technique to determine the redox state of a reversible redox couple. The dimensionless current function is calculated with the same recurrent formula (3) by appropriate adjustment of the dimensionless potential values ϕ m [20]. Generally, the chronoamperometric response in EFS depends on the SW amplitude and frequency, the number of potential cycles (i. e., time of the experiment) and the mid‐potential E m (see Figure 1).…”

“…The potential modulation used in EFS is depicted in Figure 1A. Specifically, the underlying staircase potential of conventional SWV is replaced with a constant potential (mid-potential, E m ) and SWV is transformed into SW chronoamperometry, which to some extent is similar to the early works of Smit and Wijnen [20]. The obtained chronoamperometric data in EFS can be presented as forward, backward, and net (differential) chronoamperometric curves (Figure 1B).…”

Recent Advances and Prospects of Square-Wave Voltammetry

“…Square-wave chronoamperometry is a simplified form of conventional square-wave voltammetry developed for the purpose of simplification and broadening the scope of the technique [77]. The theoretical base of this renewed idea is found in the early works of Smit and Wijnen [78][79][80], in the methodology known as cyclic potential-step method. Square-wave chronoamperometry is a pulseform chronoamperometric experiment, the excitation signal being obtained by combining a constant potential (mid-potential, Emid) with a short-duration, small potential pulses, as depicted in Figure 7A.…”