Engineered interface of three-dimensional coralliform NiS/FeS_(2)heterostructures for robust electrocatalytic water cleavage

Heterojunction structures improve the intrinsic activity of electrocatalysts by enhancing the charge transfer between the catalyst and the electrode.In this paper,the NiS/FeS_(2)heterostructured electrocatalyst is fabricated by a simple sulfidation method using an interface engineering strategy to adjust the surface electron density of the electrocatalyst.As expected,NiS/FeS_(2)electrocatalyst exhibits superior activity and durable oxygen evolution reaction(OER)stability,requiring only a low overpotential of 183 mV to achieve a current density of 10 mA·cm^(−2)and can be stable for more than 80 h,superior to NiS,FeS_(2)electrocatalyst individually,and precious RuO_(2).Notably,NiS/FeS_(2)is also a good bifunctional electrocatalyst with good overall water splitting performance,and it only requires a voltage 1.56 V to obtain a current density of 10 mA·cm^(−2)for more than 12 h.Remarkably,the NiS/FeS_(2)hybridization facilitates the formation of coral-like structures,increasing the electrochemical surface area(ECSA)and enhancing the charge transfer efficiency,thus leading to excellent electrocatalytic performance.This work proposes a constructive strategy for designing efficient electrocatalysts based on interface engineering,and lays a foundation for designing a new class of electrocatalysts.