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

Abstract

AbstractRare 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 NiOx with 3D core‐shell structure (Fe−NiS@NiCeOx) 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 NiCeOx 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@NiCeOx/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@NiCeOx/CC exhibits the best performance of the three as‐fabricated Fe−NiS@NiREOx/CC (RE=Ce, La, Pr) catalysts.