Polymetallic sulfide nanosheet arrays with composite structure as a highly efficient oxygen evolution electrocatalyst

Designing an earth-abundant and cost-effective electrocatalyst for oxygen evolution reaction (OER) is the crux to the hydrogen production by water electrolysis on industrial scale. Herein, we developed a trimetallic sulfide hybrid of CoS1.097/Fe1-xS/Ni3S2/NF nanoarrays by the combination of morphology opti-mization and interface modulation. The unique morphology of ultrathin nanosheets significantly enriches the reaction sites of the catalyst, while the abundant heterogeneous interfaces effectively regulate the local electron structure and thus intrinsically enhances the catalytic activity of the material. As a result, the catalyst delivers the superior OER performance with the ultralow overpotential of 229 mV at the cur-rent density of 50 mA cm-2 and Tafel slope of 30.2 mV dec-1. Furthermore, the current density of the material keeps constant for 50 h in 1.0 M KOH. This work proposes a strategy for the synthesis of poly -metallic sulfide catalysts with composite structure as an efficient OER catalyst by morphology optimiza-tion and interface modulation.(c) 2022 Elsevier Inc. All rights reserved.