Facilitating active species by decorating CeO2 on Ni3S2 nanosheets for efficient water oxidation electrocatalysis

Abstract In the pursuit of stable, high performance Ni-based oxygen evolution reaction (OER) electrocatalysts, modifying the local chemical compositions or fabricating hybrid nanostructures to generate abundant interfaces for improving the water oxidation activity of electrocatalysts has emerged as an effective strategy. Herein, we report the facile development of a Ni3S2-CeO2 hybrid nanostructure via an electrodeposition method. Benefiting from the strong interfacial interaction between Ni3S2 and CeO2, the electron transfer is notably improved and the water oxidation activity of Ni3S2 nanosheets is significantly enhanced. In 1.0 M KOH, the Ni3S2-CeO2 electrocatalyst achieves a current density of 20 mA cm–2 at a low overpotential of 264 mV, which is 92 mV lower than that of Ni3S2. Moreover, Ni3S2-CeO2 exhibits superior electrochemical stability. Density functional theory calculations demonstrate that the enhanced OER electrocatalytic performance of Ni3S2-CeO2 can be ascribed to an increase in the binding strength of the reaction intermediates at the Ni3S2-CeO2 interface.