Synthesize And Explore The Electrochemical Properties Of Transition Metal Sulfides Based On Carbon Nanotubes

In this paper,different metal sulfide nanocomposites were prepared on carbon nanotube matrix by hydrothermal method.A series of characterization methods were used to characterize the materials and explore their composition,morphology and different electrochemical behaviors reflected by them,which can be summarized in the following three parts:1.Using carbon nanotubes as the matrix material,the quality of NiCo₂S₄ composite on carbon nanotubes was changed by controlling the concentration and ratio of reactants such as nickel and cobalt in the solution.CNTs/NiCo₂S₄ nanocomposites were prepared by a two-step hydrothermal method.The mass ratio of CNTs to NiCo₂S₄ in CNTs/NiCo₂S₄ nanocomposites with optimal electrochemical performance was further determined.And the results show that the specific capacitance of CNTs/NiCo₂S₄ is 1428F g^-1 and the specific capacitance of NiCo₂S₄ is 733.5 F g^-1 at the current density of 1A g^-1.At the current density of 10 A g^-1,after 4000 GCD cycles,CNTs/NiCo₂S₄ can still retain 80.6%of the initial capacitance,while NiCo₂S₄ can only retain 60.2%of the initial capacitance,indicating that CNTs/NiCo₂S₄ has good charge storage capacity and stable performance.2.The rose-shaped CNTs/MoS₂ nanocomposites with unique morphology were prepared by simple hydrothermal method.The results show that the CNTs/MoS₂ have unique morphology and excellent electrochemical properties.When the current density is 1 A g^-1,the specific capacitance of CNTs/MoS₂ is 642 F g^-1.When the current density is 10 A g^-1,it still retains 85.8%of the initial specific capacitance after 5000 GCD cycles,showing good cycle stability.In addition,when the current increased from 1 A g^-1 to 20A g^-1,the power density increased from 275.03 W kg^-1to 5500.8 W kg^-1,and the energy density also increased from 22.92 Wh kg^-1 to 42.27 Wh kg^-1.showing quite good electrochemical performance.3.Furthermore,CNTs/MoS₂ were modified by ZnS to prepare CNTs/MoS₂@ZnS nanocomposites,and their electrochemical properties were optimized.The results show that when the current increases from 1 A g^-1 to 20 A g^-1,the multiplier performance of CNTs/MoS₂ is 37.4%,the highest power density is 5500.8 W kg^-1,and the highest energy density is 42.27 Wh kg^-1.While CNTs/MoS₂@ZnS has a magnification performance of 106%,a maximum power density of 9800.61 W kg^-1,and a maximum energy density of 71.98 Wh kg^-1.In conclusion,CNTs/MoS₂@ZnS has better electrochemical properties and is a potential electrode material for supercapacitors.