Zinc-induced local coordination modulation and electrochemical reconstruction of nickel-iron layered double...

Dynamic electrochemical reconstruction critically governs the oxygen evolution reaction (OER) activity of NiFe layered double hydroxides (LDHs), yet deliberately steering this process through sacrificial Zn regulation remains underexplored. Herein, Zn-modulated NiFe LDH nanosheets were constructed to regulate the reconstruction pathway and active-interface formation during electrochemical activation. The optimized catalyst requires overpotentials of only 218 and 266 mV to deliver current densities of 10 and 100 mA cm^-2, respectively, together with a Tafel slope of 34 mV dec^-1 and stable operation for over 150 h at 100 mA cm^-2. Experimental results support the preferential dissolution of Zn during activation and the accompanying formation of a NiFeOOH-rich reconstructed interface with an increased contribution of high-valence Ni species. Density functional theory calculations further show that OH* adsorption is more favorable at the reconstructed Ni site than at the residual Zn site, with adsorption energies of -0.587 and - 0.114 eV, respectively. Zn removal also decreases the maximum uphill free-energy change of the OH* → O* conversion from 1.693 eV on NiFeOOH to 1.482 eV on Zn_v-NiFeZnOOH, while the investigated adsorbate evolution mechanism is thermodynamically more favorable than the lattice‑oxygen-mediated pathway. These findings establish sacrificial Zn regulation as an effective strategy for directing beneficial reconstruction and constructing active oxyhydroxide interfaces in NiFe-based electrocatalysts.