Surface electron transfer enhanced by molecular oxygen: Droplet and bulk mode experiments on boron-doped diamond electrodes
| Autoři | |
|---|---|
| Rok publikování | 2025 |
| Druh | Článek v odborném periodiku |
| Časopis / Zdroj | Journal of Electroanalytical Chemistry |
| Fakulta / Pracoviště MU | |
| Citace | |
| www | https://doi.org/10.1016/j.jelechem.2025.119329 |
| Doi | https://doi.org/10.1016/j.jelechem.2025.119329 |
| Klíčová slova | Screen-printed boron-doped diamond electrode; Surface transfer doping; Drop and bulk modes; Oxygen effect; Elimination voltammetry; Impedance spectroscopy; Mott-Schottky analysis |
| Popis | The three-electrode screen printed boron-doped diamond (SP/BDD) sensor fabricated by chemical vapor deposition (CVD) on an alumina substrate allowed testing its different electroanalytical performance in terms of: (1) the termination of the SP/BDDE surface (H- or O-termination), (2) the immersion mode of the SP/BDDE in the analyte solution (B - bulk mode) and in the drop experiment (D - drop mode), and (3) the presence and absence of atmospheric oxygen. The electrochemical methods (CV - cyclic voltammetry, EVLS - elimination voltammetry with linear scan, EIS - electrochemical impedance spectroscopy) were complemented by methods that characterize the surface properties of the electrode material (Raman spectroscopy, SEM - scanning electron microscopy, XPS - X-ray photoelectron spectroscopy, OCA - optical contact angle). Mott-Schottky analysis demonstrated a higher density of free charge carriers and a closer localization of the valence band (VB) to Fermi level for Htermination than for O-termination of surfaces, therefore further experiments were performed on the H-terminated SP/BDDE. The B and D mode tests in the absence and presence of atmospheric oxygen using the redox probe [Fe(CN)6]3- /4- demonstrated a significant difference in both the heterogeneous charge transfer rate constants and charge transfer resistance values. The H-terminated SP/BDDE surface and the D-mode experiment in the presence of O2 provided the best electroanalytical performance of this screen-printed diamond electrode. The O2-enhanced surface electron transfer was discussed in the context of the electrochemical potential model of boron-doped diamond and the used electrolyte. |
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