A Versatile System for Arbitrary Function Large‐Amplitude Fourier Transformed Voltammetry

Abstract

A novel low-cost instrument for arbitrary function large-amplitude Fourier transformed voltammetry was developed. Description of both hardware and software was given in detail in this paper. A micro-control-unit (MCU) in combination with a field programmable gate array (FPGA) was designed to act as the controller of the instrument. Profiting from the built-in USB2.0 standard interface of the MCU, vast amount of data to/from the high resolution digital-to-analog converter (DAC)/analog-to-digital converter (ADC) then could be exchanged with computer in realtime, instead of being temporarily stored at the capacity limited memory of the instrument which always restricted the length of sampling time and the size of the collected data set. In the [Fe(CN) 6 ] 4þ/3þ system, by superimposing a sinusoidal waveform with an amplitude of 120 mV onto a triangular potential and then applying to a macro electrode through the instrument, voltammograms up to the eighth harmonic could be well resolved by FT-IFT method. Excellent agreement was attained with Bonds similar experiment [Anal. Chem. 76 (2004) 3619] in respect of the shape and relative peak height of each harmonic. With the simply structured instrument, stable performance, flexible and versatile function was achieved. Arbitrary forms of AC perturbation which may not necessarily be sinusoidal or square-wave or other regular formed periodic signal could be synthesized and superimposed onto a DC potential as the excitation signal with this instrument. Some more useful electrode process information was expected to unveil by utilizing the FT-IFT algorithm to dissect the response signal.

A Simultaneous Study of Kinetics and Thermodynamics of Anion Transfer across the Liquid/Liquid Interface by Means of Fourier Transformed Large-Amplitude Square-Wave Voltammetry at Three-Phase Electrode

“…The stability of the system was checked by performing consecutive dc cyclic voltammetry with a CHI660B electrochemical workstation (Shanghai, China) prior to the FT-SWV experiments. Home-built instrumentation used for the FT-SWV experiments and corresponding signal processing algorithms are available elsewhere . All FT-SWV experiments were arranged so that exactly 2 n (typically, n = 16−18) points of current data were collected at a constant sampling rate of 12 kHz.…”

“…Home-built instrumentation used for the FT-SWV experiments and corresponding signal processing algorithms are available elsewhere. 23 All FT-SWV experiments were arranged so that exactly 2 n (typically, n=16-18) points of current data were collected at a constant sampling rate of 12 kHz. A moving average of 8 data points was used for data collection.…”

An Experimental Investigation of Quasireversible Maximum of Azobenzene on Mercury Electrode by Fourier Transformed Square‐Wave Voltammetry

“…Details of the instrumentation used in FT-SWVare available elsewhere [30]. The sampling rate was selected to ensure that every data set in the experiment has 2 k points (k ¼ 16 -18) in order to accelerate FT processing [31,32].…”

Ion Selective Detection Based on the Nuances of the Kinetic Fingerprint for Ion Transfer at Soft Interfaces

“…The obtained time-domain current response is then subject to FT to get the power spectrum in which the dc component, fundamental, second-, and higher-order harmonics are separated . Afterward, each time-domain component (represented as current magnitude and phase angle) can be recovered/resolved through band selection, filtering, and inverse FT of the power spectrum . FT-V refers to the large-amplitude FT-V throughout the whole text by default.…”

“…38 Afterward, each time-domain component (represented as current magnitude and phase angle) can be recovered/resolved through band selection, filtering, and inverse FT of the power spectrum. 42 FT-V refers to the large-amplitude FT-V throughout the whole text by default. A large amplitude of a single sine-wave perturbation will induce stronger higher harmonics that are caused by the nonlinear Faradaic process, whereas the linear charging current is mainly distributed at the fundamental and lower harmonics.…”