Figure 4
(A–F) Electrochemical characterization of self-supported electrodes recorded in 0.5 M NaOH solution at 50 mV s−1 under room temperature. (A) CV profiles of the applied electrodes recorded in the absence of ethanol. (B) CV spectra of the proposed electrodes collected in the presence of 0.5 M ethanol. (C) Current–time relationship of the electrodes obtained by CA technique measured in 0.5 M ethanol at a fixed applied potential of 0.7 V for 18,000 s and compared with the commercial Pt/C electrode (Fig. 5C-curve f). (D) Relative current of the investigated electrodes measured at the end of the current–time analyses. (E) Net current of the C-NT/Co3O4 CPs/3D PNi electrode as a function of the effective number of cycles; the inset (g) shows the plot of the relative current and the corresponding number of cycles used. (F) EIS profiles of the electrodes recorded in the presence of 0.5 M C2H5OH at 5 mV amplitude. (F, inset) The solution resistance (Rs) and charge-transfer resistance (Rct) in the electrode and at the electrode–electrolyte interface, respectively, as well as the redox capacitance (C), are the equivalent circuit variable described in the Nyquist plots.
