Abstract
In order to study the properties of single-crystal boron-doped diamond electrodes for electroanalysis, (100) and (111) boron-doped homoepitaxial single-crystal and polycrystalline diamond thin films were deposited by means of microwave plasma-assisted chemical vapor deposition. Features in the cyclic voltammograms (CVs) for aqueous H2SO4 supporting electrolyte and Fe(CN)63-/4- in aqueous Na2SO4 for polycrystalline electrodes were dominated by behaviour typical of (111) single-crystal facets, rather than (100) facets. Apparent heterogeneous electron-transfer rate constants (k0) for various redox systems were estimated with CV simulation at polycrystalline, (111) and (100, off-axis, 4°). Based on comparison with the Marcus model, the behavior of the k0 values, except for that of Fe(CN)63-/4-, and indicates apparent outer-sphere electron-transfer, but with a lower density of states compared to glassy carbon or typical metal electrodes. The (111) homoepitaxial film performed better than a polycrystalline film in the cyclic voltammetric detection of serotonin, with signal-to-background ratios of 5 and 2, respectively. Single-crystal diamond may thus be an even more optimal electrode material for electroanalysis than polycrystalline diamond, which has been shown to have superior characteristics as an electrode material.
Original language | English |
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Pages (from-to) | E179-E184 |
Journal | Journal of the Electrochemical Society |
Volume | 149 |
Issue number | 6 |
DOIs | |
Publication status | Published - 2002 Jun 1 |
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Renewable Energy, Sustainability and the Environment
- Surfaces, Coatings and Films
- Electrochemistry
- Materials Chemistry