Abstract

An electrically conducting composite electrode consisting of a ceramic paper substrate, which has been densely coated with carbon nanofibers of ca. 100 nm diameter, is employed in the presence of 24 kHz (8 W cm-2) power ultrasound emitted from a glass horn system. The carbon composite electrode remains stable during prolonged use in the presence of ultrasound. Sonovoltammetric limiting currents for the reduction of Ru(NH3) 63+, the oxidation of hydroquinone, and the reduction of colloidal hydrous iron oxide are reported. A comparison of sonovoltammograms obtained at a porous carbon nanofiber-ceramic composite electrode with those obtained at a conventional glassy carbon electrode shows that (i) the average mass transport limited current density at carbon nanofiber-ceramic composite electrodes is increased by approximately one order of magnitude, and (ii) due to the porous topography of the electrode surface, molecules remain resident within the diffusion layer for a longer period of time. Colloidal hydrous iron oxide is not reduced at conventional glassy carbon electrodes but can be reduced at the porous carbon nanofiber-ceramic composite electrode, presumably due to a more effective particle-carbon nanofiber electrode surface interaction.

Original languageEnglish
Pages (from-to)3411-3417
Number of pages7
JournalElectrochimica Acta
Volume48
Issue number23
DOIs
Publication statusPublished - 15 Oct 2003

Funding

F.M. thanks the Royal Society for the award of a University Research Fellowship. M.A.M. thanks the Faculty of Science, Loughborough University, for a PhD studentship.

Keywords

  • Carbon nanofibers
  • Ceramic fibers
  • Colloidal redox systems
  • Nanoparticles
  • Porous electrodes
  • Ultrasound
  • Voltammetry

ASJC Scopus subject areas

  • General Chemical Engineering
  • Electrochemistry

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