Fig. 4.
Electrocatalytic water oxidation performance. a 95% iR-corrected polarization curves of reference Ni(OH)2-r, w-Ni(OH)2-e, and w-Ni(OH)2 samples. b The overpotentials required for j = 10, 50, 80 mA cm−2 with different electrodes. c Tafel plots for Ni(OH)2-r, w-Ni(OH)2-e, and w-Ni(OH)2 electrodes. d EIS Nyquist plots of the Ni(OH)2-r, w-Ni(OH)2-e, and w-Ni(OH)2 electrodes under the bias potential of 1.48 V. e Chronopotentiometric measurements of OER at various current densities using w-Ni(OH)2 as a catalyst. All the tests were carried out in 1 M KOH solution (O2-saturated)