Fig. 3: Electrocatalytic oxygen evolution performance of the NiFeB hydroxide nanosheets compared with the B-free NiFe hydroxide nanosheets.
a OER polarization curves (95% iR compensation). The current densities were normalized to the geometric area of the electrode. b Comparison of current densities observed with different catalysts at 1.53 V vs. RHE. The current densities were normalized to the geometric area of the electrode and the electrochemically active surface area (ECSA), respectively. c Comparison of the OER activity of the NiFeB hydroxide nanosheets with those of the NiFe hydroxide nanosheets and typical nonnoble metal catalysts reported previously. Data were estimated from the OER polarization curves reported in refs. 13,22,34,54, and 20. d Differential pulse voltammetry curves (95% iR compensation). The currents for the NiFe hydroxide nanosheets were multiplied by 5 for clear demonstration (dotted curve). e Nyquist plots of the catalysts recorded at a constant potential of 1.50 V vs. RHE. Inset: equivalent circuit used in fitting the plot. f Chronopotentiometric curves for the catalysts at current densities of 10, 100, and 500 mA cmgeo−2. No iR compensation was applied in the measurements.
