How Many Molecules are Required to Obtain a Steady Faradaic Current from Mediated Electron Transfer at a Single Nanoparticle on a Supporting Surface?

Kätelhön, Enno; Krause, Kay J.; Wolfrum, Bernhard; Compton, Richard G.

doi:10.1002/cphc.201301197

Cited by 7 publications

(6 citation statements)

References 19 publications

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“…The carbon nanotubes are highly conductive due to their multiwalled structure, 35 and their large sizes preclude current fluctuations relating to a shot noise process arising from the finite nature of the solution-phase hydrogen concentration. 36 Given this, it is reasonable to conclude that these fluctuations are associated with the electrical connection between the electrode and nanoparticle. Of the cases featuring similar nanoparticle residence times, similar fluctuations have been observed, for example, in the electrochemical response of individual spherical gold nanoparticles catalyzing proton reduction on impact with a carbon fiber electrode.…”

Section: Resultsmentioning

confidence: 98%

Single Nanotube Voltammetry: Current Fluctuations Are Due to Physical Motion of the Nanotube

Hodson

Batchelor‐McAuley

et al. 2016

J. Phys. Chem. C

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Nanoimpacts of single palladium-coated carbon nanotubes on a gold substrate are studied to elucidate the origins of the fluctuation in the current–time response of the hydrogen oxidation reaction mediated at its surface. The chronoamperometric and cyclic voltammetric responses from a single nanotube immobilized on the gold surface were compared to analogous data on a carbon substrate to determine the possible influence of substrate material on the nanotube–electrode electrical contact. No significant distinction between the gold and carbon was found, indicating in light of the considerable differences in the substrate materials’ intrinsic electronic structures that it is the nanomotion of a nanotube at the electrode surface which is likely responsible for the observed current modulation. This nanomotion creates a varying contact resistance, to which the noise in the current–time signal of the mediated reaction is attributed. In addition, stochastic ex-situ adsorption of single nanotubes onto the gold electrode followed by careful drying of the electrode surface was found to drastically reduce the current fluctuation, again implying that a contact resistance arising from physical motion of the nanotube at the electrode is responsible for the modulation of current.

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Section: Resultsmentioning

confidence: 98%

Single Nanotube Voltammetry: Current Fluctuations Are Due to Physical Motion of the Nanotube

Hodson

Batchelor‐McAuley

et al. 2016

J. Phys. Chem. C

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“…The cyclic voltammograms of the individual tubes evidence that the noise in the current is intimately associated with the Faradaic charge transfer and is not capacitative in origin. Due to the magnitude of the currents involved it is unlikely that these fluctuations are due to shot noise associated with the discrete nature of the charge carrier (hydrogen in the present case) . Second, the use of multi‐walled carbon nanotubes renders it unlikely that the fluctuations arise due to conduction along the length of the tube .…”

Section: Figurementioning

confidence: 95%

Single Nanoparticle Voltammetry: Contact Modulation of the Mediated Current

Batchelor‐McAuley

Whitby

et al. 2015

Angewandte Chemie

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The cyclic voltammetric responses of individual palladium‐coated carbon nanotubes are reported. Upon impact—from the solution phase—with the electrified interface, the nanoparticles act as individual nanoelectrodes catalyzing the hydrogen‐oxidation reaction. At high overpotentials the current is shown to reach a quasi‐steady‐state diffusion limit, allowing determination of the tube length. The electrochemical response of the individual nanotubes also reveals the system to be modulated by the electrical contact between the electrode and carbon nanotube. This modulation presents itself as fluctuations in the recorded Faradaic current.

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“…Cutress et al for instance used aG PU-based random walk simulation to investigate cyclic voltammetry [119] and potential-step chronoamperometry [120] at low concentrations, while Kätelhçn and Compton focusedo nt he noise-characteristics of the mediated Faradaic current across an anoparticle impactingo naFaradaically inactive electrode surface. [121] Aside from the modelling of systems at low concentrations, random walk simulations can furtherb e employed to investigate noise characteristics of electrochemical sensors in nanofluidic devices. Hereby, applications include the modelling of methods for single molecule detection [122] as well as the simulation [117,123] of spectra obtained from electrochemicalcorrelation spectroscopy (ECS).…”

Section: Finite Electron Transfer Kineticsmentioning

confidence: 99%

Recent Advances in Voltammetry

et al. 2015

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Recent progress in the theory and practice of voltammetry is surveyed and evaluated. The transformation over the last decade of the level of modelling and simulation of experiments has realised major advances such that electrochemical techniques can be fully developed and applied to real chemical problems of distinct complexity. This review focuses on the topic areas of: multistep electrochemical processes, voltammetry in ionic liquids, the development and interpretation of theories of electron transfer (Butler–Volmer and Marcus–Hush), advances in voltammetric pulse techniques, stochastic random walk models of diffusion, the influence of migration under conditions of low support, voltammetry at rough and porous electrodes, and nanoparticle electrochemistry. The review of the latter field encompasses both the study of nanoparticle-modified electrodes, including stripping voltammetry and the new technique of ‘nano-impacts’.

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How Many Molecules are Required to Obtain a Steady Faradaic Current from Mediated Electron Transfer at a Single Nanoparticle on a Supporting Surface?

Cited by 7 publications

References 19 publications

Single Nanotube Voltammetry: Current Fluctuations Are Due to Physical Motion of the Nanotube

Single Nanotube Voltammetry: Current Fluctuations Are Due to Physical Motion of the Nanotube

Single Nanoparticle Voltammetry: Contact Modulation of the Mediated Current

Recent Advances in Voltammetry

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