3.3. Electrochemical response of the hybrid diamond/graphite
electrodes
The electrochemical responses of the electrode deposited under
8% methane concentration in aqueous and organic solutions are
carried out in [Fe(CN)6]3−/4− and ferrocene solutions, as shown
in Fig. 5. In Fig. 5(a) and (c), the Eps are about 73 mV and
71 mV for [Fe(CN)6]3−/4− and ferrocene, respectively, at a scan
rate of 10 mV/s on the diamond/graphite electrode, close to the
Ep on a high quality B-doped diamond electrode, i.e., 71 mV
for [Fe(CN)6]3−/4− [36]. The peak currents for both anodic and
cathodic peaks are proportional to the square root of the scan
rate with r2 ≥
0.999 in both solutions, shown in Fig. 5(b) and
(d). Such a dependence on the scan rate indicates that electrode