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 language | English |
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Pages (from-to) | 3411-3417 |
Number of pages | 7 |
Journal | Electrochimica Acta |
Volume | 48 |
Issue number | 23 |
DOIs | |
Publication status | Published - 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