Fe‐Facilitated Deep Reconstruction of Ni ₃ S ₂ Toward Superior Oxygen Evolution

ABSTRACT The advancement of effective and stable non‐precious metal‐based catalysts for oxygen evolution reactions (OER) with a low‐cost and simple technique is essential for the practical application of rechargeable zinc–air battery (ZAB). However, facilitating the deep reconstruction of electrocatalysts to form active species remains a significant challenge. Here, a simple two‐step method composed of impregnation and carbonization process is proposed to synthesize N, S co‐doped microcrystalline cellulose‐derived carbon‐supported nickel sulfide (Ni ₃ S ₂ ) nanoparticles. The in situ Raman reveals that Fe substitution promotes the reconstruction of Ni ₃ S ₂ , accompanied by the cleavage of the Ni–S bond, leading to the deep reconstruction into (Ni,Fe)OOH (DR‐(Ni,Fe)OOH) during the OER. Moreover, density functional theory calculations reveal that Fe substitution induces a downshift in the energy band structure, which lowers the energy barriers and thereby improves the kinetics of the OER. The generated DR‐(Ni,Fe)OOH delivers a relatively low overpotential of 260 mV and superior durability for 50 h under OER condition. The ZAB incorporating DR‐(Ni,Fe)OOH + Pt/C as the air cathode demonstrates superior efficiency and durability, achieving a peak power density of 188.3 mW cm ⁻² , a specific capacity of 811.1 mAh g ⁻¹ , and long‐term stability exceeding 200 h.