Core-bishell NiFe@NC@MoS for boosting electrocatalytic activity towards ultra-efficient oxygen evolution reaction.

Designing and developing suitable oxygen evolution reaction (OER) catalysts with high activity and stability remain challenging in electrolytic water splitting. Hence, NiFe@NC@MoS core-bishell composites wrapped by molybdenum disulphide (MoS) and nitrogen-doped graphene (NC) were prepared using hydrothermal synthesis in this research. NiFe@NC@MoS composite exhibits excellent performance with an overpotential of 288 mV and a Tafel slope of 53.2 mV·dec at a current density of 10 mA·cm in 1 M KOH solution, which is superior to commercial RuO. NC and MoS bishells create profuse edge active sites that enhance the adsorption ability of OOH* while lowering the overall overpotential of the product and improving its oxygen precipitation performance. The density function theory(DFT) analysis confirms that the layered MoS in NiFe@NC@MoS provides additional edge active sites and enhances electron transfer, thus increasing the intrinsic catalytic activity. This research paves a novel way for developing OER electrocatalysts with excellent catalytic performance.