Fe−NiS Nanorod Encapsulated in Ce‐doped NiO_x Shell for Oxygen Evolution Reaction

Abstract Rare earth (RE) elements are promising to improve the property of catalysts due to their distinctive 4 f electron orbital. Herein, a heterogeneous material of Fe−NiS nanorods encapsulated in Ce‐doped NiO_x with 3D core‐shell structure (Fe−NiS@NiCeO_x) was constructed on carbon cloth (CC) through a straightforward solvothermal reaction and a subsequent electrodeposition for enhancing the electrocatalytic performance towards oxygen evolution reaction (OER) in alkaline medium. The strategy facilitates a synergy among the components, including an enlarged electrochemical active area of Fe−NiS by the involvement of Fe and an ameliorated durability of Fe−NiS nanorod by encapsulated in NiCeO_x shell. Furthermore, a flexible valence alternation between Ce (III) and Ce (IV) speeds up the charges transfer between Ni(II) and Ni(III). In 1.0 mol L⁻¹ KOH, the Fe−NiS@NiCeO_x/CC electrode shows the lowest overpotential of 230 mV to achieve the current density of 50 mA cm⁻², the smallest Tafel slope of 63 mV dec⁻¹ and a superior durability with only a potential fluctuation of 0.01 V on a chronopotentiometry curve within 24 h. Further research suggests that Fe−NiS@NiCeO_x/CC exhibits the best performance of the three as‐fabricated Fe−NiS@NiREO_x/CC (RE=Ce, La, Pr) catalysts.