Construction And Performance Study Of MoS₂-Based Alkaline Hydrogen Evolution Catalyst

In recent years,hydrogen energy has been considered a promising fuel due to its cleanliness and high energy density.Electrocatalytic hydrogen evolution reaction（HER）is a fast,direct,and effective method for hydrogen production.Pt-based materials are considered the most ideal HER electrocatalysts so far,but their practical applications are severely limited by resource scarcity,high cost,and instability.Therefore,finding a cost-effective HER catalyst has become the most urgent goal for researchers at present.MoS₂has made significant progress in the HER field due to its low price and wide distribution.However,the MoS₂conductivity of the 2H phase is poor and the basal surface is catalytically inert,which seriously affects its electrocatalytic activity.In order to solve this problem,the transition metal sulfide and MoS₂were introduced to construct the heterostructure.MoS₂/NiS₂ composite material was synthesized by hydrothermal synthesis using carbon cloth as a conductive substrate.The unique structure of MoS₂/NiS₂composite material facilitates contact with electrolyte and increases the electrochemical activity specific surface area.MoS₂/NiS₂composite improves the catalytic activity of a single active site because of the synergistic effect between different components.When the current density reaches 10 m A cm^-2,the overpotential is 93 mV.After 3000 CV cycles,the overpotential only slightly decreased.After 65 hours of chronopotentiometry testing,there was no significant change in overpotential.In order to further improve the conductivity and electrocatalytic activity of the composite material,MoS₂/CoS₂composite material was synthesized.The synergistic effect between CoS₂and MoS₂at the heterogeneous interface endows the hybrid with higher HER catalytic activity than a single component.In situ screening test showed that the main active site came from MoS₂rather than CoS₂.After annealing treatment,the catalytic performance of the sample was further improved.In 1M KOH,when the current density is 10 m A cm^-2,the overpotential of the composite material is only 67mV.In addition,there was no significant attenuation after 65 hours of chronopotentiometry testing at an overpotential of 20 m A cm^-2,indicating that the annealed MoS₂/CoS₂exhibits excellent cycling durability.