Electronic Modulation–Driven Dual Self‐Reconstruction Neural‐Like NiFe Sulfides for Durable and Efficient Alkalized Water Splitting

Surface reconstruction is pivotal to forming active sites during the electrocatalytic process of water splitting, yet achieving controllable reconstruction toward highly active and durable catalytic states remains challenging. Herein, we report a Fe 9 Ni 9 S 16 ‐(Ni,Fe)S/PNFF pre‐catalyst that undergoes flexible dual self‐reconstruction into V‐(Ni,Fe) 3 S 2 (sulfur‐defect:V) under cathodic and γ‐(Ni,Fe)OOH‐SO 4 2− under anodic conditions. In‐situ/ex‐situ characterizations and theory (DFT) calculations reveal that Fe incorporation modulates the Ni d‐band center, which promotes sulfur vacancy formation, enhances H* adsorption, and accelerates the HER kinetics. Concurrently, the SO 4 2− species adsorbed on γ‐(Ni,Fe)OOH inhibit OH − adsorption and promote O* to OOH conversion, boosting OER performance. Benefiting from this synergy, the catalyst achieves low overpotentials of 420 mV (HER) and 391 mV (OER) at 2 A cm −2 in 1 M KOH, and operates stably over 1000 h at 1 A cm −2 . Furthermore, in an anion exchange membrane water electrolyzer (AEMWE) device, a cell voltage of 2.05 V is achieved at 1000 mA cm −2 with a stable operation over 200 h at 60°C (6 M KOH). This work offers a dual self‐reconstruction strategy for engineering chalcogenide electrocatalysts toward an efficient, durable overall water splitting.