Interfacial coupling of NiSe in heterostructures promotes electrocatalytic hydrolysis of MoS.

Molybdenum sulfide (MoS) has attracted much attention as a potential catalyst for the oxygen evolution reaction (OER), but its unique low activity and low edge active centers limit its electrocatalytic activity. In this study, catalysts were prepared by growing NiSe nanoclusters onto MoS substrates electrodeposition; ultrathin MoS nanosheets and NiSe nanoclusters were cross-linked with each other to form a unique three-dimensional rosette structure; and MoS@NiSe catalysts were successfully synthesised, which significantly improved bifunctional catalytic performance. The synthesised MoS@NiSe catalysts exhibited good electrochemical performance: overpotentials required to satisfy the HER and OER processes at a current density of 10 mA cm in 1 M KOH were 80 mV and 254 mV, respectively. When applied as a cathode and anode to assemble a bifunctional electrode system, the MoS@NiSe||MoS@NiSe electrolytic cell system required only 1.54 V to achieve 10 mA cm in an alkaline electrolyte, which exceeded the value of most of the bifunctional catalysts reported in the literature to date. In addition, the catalyst maintained good surface structure and catalytic performance after a 24 h stability test. This study provides a new idea for the improvement and design of MoS-based bifunctional catalysts and provides an important reference for research in the field of clean energy.