Preparation And Performance Research Of Molybdenum Disulfide-based Composite Catalyst In Hydrogen Evolution Reaction

Hydrogen has been recognized as promising green energy source due to the advantages of high energy conversion efficiency and renewable.As a sustainable hydrogen production technology,electrolyzed water has been widely studied.At present,Pt-based catalysts still are the state-of-the-art electrocatalysts to drive HER.Therefore,the development of alternative non-noble metal catalysts is crucial.The construction of a composite catalyst is one of the main strategies to improve the performance of the hydrogen evolution reaction（HER）.Experimental and theoretical studies have shown that Mo S₂ and spinel sulfide have higher HER activity.Therefore,a series of Mo S₂-based catalysts was prepared and the HER performance of samples in alkaline environment was systematically studied.The main content and experimental results are as follows:A series of Cu Co₂S₄-Mo S₂ with different proportions were prepared by two-step method and successfully loaded on the foamed nickel by the coating method.Furthermore,the HER performance of the electrode was systematically investigated.The result shows that the catalytic activity of Cu Co₂S₄-3Mo S₂ electrode is the highest,and when the cathode current density is 10m A·cm^-2,the overpotential only needs 126.3m V,and the Tafel slope is only91.4m V·dec^-1.The good performance can be attributed to its Tremella-like spherical structure,which can greatly expose the catalytic active sites and also facilitate the contact of the electrolyte.Using the pretreated carbon cloth as the substrate,the vertically distributed nano-sheet structure Mo S₂/Fe Co₂S₄/CC electrode was prepared by two-step hydrothermal method.The test result shows that when the cathode current density is 10m A·cm^-2,the overpotential of Mo S₂/Fe Co₂S₄/CC only needs 161m V,and the Tafel slope is only 98.4m V·dec^-1.Under the condition of a voltage of 228m V,the stability was studied by the chronoamperometry（CA）test.After 24 hours,the current density has decreased by 20.8%.The great stability and catalytic activity are due to the support and dispersion of the carbon cloth substrate and the synergy between Mo S₂ and Fe Co₂S₄.The 1T-Mo S₂/Ni Co₂S₄/CC composite material was successfully synthesized by two-step hydrothermal method to grow in situ with carbon cloth as a substrate.When the cathode current density is 10m A·cm^-2 and 100m A cm^-2,the overpotential of 1T-Mo S₂/Ni Co₂S₄/CC is107m V and 200m V,respectively,and the Tafel slope is only 66.4 m V·dec^-1.Under the condition of a voltage of 170m V,the initial current density was 51m A cm^-2,and the current density retained 86%after the 24-hour CA test.The samples after the CA test was analyzed by XRD,SEM,XPS,etc.The results showed that there was no significant change in the samples before and after the test.The excellent performance is due to its unique hydrangea-like structure,high content of 1T-Mo S₂（63%）and the synergistic catalytic effect between1T-Mo S₂ and Ni Co₂S₄.