Bimetallic active site nuclear-shell heterostructure enables efficient dual-functional electrocatalysis in alkaline media

Hydrogen,as a green and clean next-generation fuel,is a key to achieving the goal of carbon neutrality.Constructing an electrocatalyst with bifunctional hydrogen evolution and oxygen evolution activity in the same electrolyte is a key technology for producing hydrogen via water splitting.Herein,a bimetallic active site catalyst,which possessed an edge-riched MoS_(2)nanoflakes array vertically growing on cubic CoS_(2),forming a nuclear-shell heterogeneous configuration,termed CSC-Mo S_(2)@Co S_(2).was reported The optimal CSC-Mo S_(2)@Co S_(2)-24 possessed good dualfunctional electrocatalytic activity(hydrogen evolution(HER),10 m A·cm^(-2)@241.5 m V and oxygen evolution(OER),10 m A·cm^(-2)@350 m V).Especially,CSC-Mo S_(2)@CoS_(2)-24 exhibited an extremely high mass activity for HER,and only required an overpotential of~550 m V when reaching a large current density of 1422 m A·mg^(-1),which was20.6-fold that of the bulk CoS_(2)(69 m A·mg^(-1)),as well as exhibiting stability of up to 100 h.The good electrocatalytic performance was attributed to the nuclear-shell heterostructure of Mo S_(2)@CoS_(2)hybrid could bring critical synergies,improving efficient mass transfer and electron transfer processes between Co S_(2)and Mo S_(2),which collaboratively promoted the electrocatalytic kinetics.It is foreseeable that the method proposed in this work will have guiding value for the preparation of dual-functional electrocatalysts with multi-interface heterostructures by assembling layered sulfides on cubic sulfides.