fig4

From: Unveiling proton-regulated Mo=O/Mo-O^- centers in reconstructed Ni₂Mo-NiOOH/MoO_x interfaces toward accelerated proton-coupled electron transfer for urea oxidation reaction

Unveiling proton-regulated Mo=O/Mo-O<sup>-</sup> centers in reconstructed Ni<sub>2</sub>Mo-NiOOH/MoO<sub>x</sub> interfaces toward accelerated proton-coupled electron transfer for urea oxidation reaction

Figure 4. Electrocatalytic UOR performance characterization of various catalysts. (A) LSV curves of Ni₂Mo-NiOOH/MoO_x, Ni₂Mo/NF, Ni-NiOOH and Ni/NF (Inset: Comparison of potential differences relative to the OER equilibrium potential for different catalysts at specific current densities); (B) Corresponding Tafel slope curves (R² values above 0.95); (C) Nyquist impedance plots and equivalent circuit model; (D) Bode phase plots; (E) C_dl plots (R² values above 0.99); (F) ECSA-normalized LSV curves; (G) LSV curve comparison between UOR and OER of Ni₂Mo-NiOOH/MoO_x; (H) 300 h i-t test of Ni₂Mo-NiOOH/MoO_x at the current density of 100 mA·cm^-2, with the LSV curves before and after the stability test shown in the inset; (I) Comparison of the potential of Ni₂Mo-NiOOH/MoO_x and other UOR catalysts at a current density of 100 mA·cm^-2. NF: Nickel foam; LSV: linear sweep voltammetry; UOR: urea oxidation reaction; OER: oxygen evolution reaction; ECSA: electrochemically active surface area; C_dl: double-layer capacitance.