Efficient and Stable Alkaline Oxygen Evolution on Fe/Co Co-Doped NiSe.

The slow kinetics of the anodic oxygen evolution reaction (OER) impose a major limitation on overall water electrolysis, creating a demand for highly active catalysts. Transition metal selenides (TMSs) offer favorable electrical conductivity, inexpensive constituents, and adjustable electronic configurations; however, their inherent catalytic activity is still insufficient. In this study, nanorod-like Fe/Co co-doped NiSe (Fe,Co-NiSe) was prepared by hydrothermally forming NiSe and subsequently introducing Fe and Co through a simple soaking treatment. The simultaneous incorporation of Fe and Co effectively tunes the electronic structure of NiSe. Raman measurements performed in situ show that introducing Fe/Co favors the generation of NiOOH-type oxyhydroxide species, thereby enhancing OER activity. 18O-labeling differential electrochemical mass spectrometry confirms that Fe,Co-NiSe follows the conventional adsorbate evolution mechanism. Density functional theory (DFT) analysis further indicates that Fe-induced electronic redistribution at Co sites raises the Co d-band position and reduces the Gibbs energy required for the kinetically limiting *O → *OOH conversion. Consequently, under alkaline conditions, Fe,Co-NiSe reaches 10 mA cm-2 at an overpotential of 229 mV and sustains 50 mA cm-2 for 300 h. When employed as the anodic electrode in an anion exchange membrane (AEM) water electrolyzer coupled with Pt/C, this electrolyzer delivers 1 A cm-2 while registering a cell voltage of 1.84 V.