Improvement Of Electrochemical Performance Of Vertical Molybdenum Disulfide Nanosheets Based On Intercalation Method

Environment-friendly energy and efficient sustainable equipments of energy storage and conversion were essential for the development of modern society.Molybdenum disulfide?MoS₂?was a two-dimensional layered material of graphene-like.Due to its unique structure,it was worth researching and appling in optoelectronics and electrochemistry.Here,vertical molybdenum disulfide nanosheets were prepared on glassy carbon substrates by chemical vapor deposition?CVD?,and their electrochemical performances were investigated in electrocatalytic hydrogen evolution catalysts and supercapacitor electrodes.The electrochemical performance of molybdenum disulfide was improved by lithium ion intercalation.Chemical vapor deposition?CVD?was an effective method for the preparation of large-area,large-size,and high-quality MoS₂.The vertical morphology of MoS₂nanosheets had high specific surface area,rich marginal activity sites,and excellent combination with substrate.There was a great potential in electrocatalytic hydrogen evolution and supercapacitor electrodes.In this dissertation,through CVD method,molybdenum oxide?MoO₃?and sublimed sulfur powder?99.5%,Analytical Reagent?as the molybdenum source and sulfur source,respectively.Vertical MoS₂ nanosheets was prepared on a glassy carbon substrate,and they were clearly observed by scanning electron microscopy?SEM?.Then,we recorded the Raman spectroscopy characterization and electrochemical test of the sample.The low conductivity and electron mobility of MoS₂ are the main reasons that limit the application of MoS₂.Vertical layered MoS₂ has high specific surface area and abundant edge active sites.Increasing the conductivity and electron mobility of MoS₂ and reducing the charge transfer resistance between electrodes and electrolytes can improve the hydrogen evolution efficiency and capacitance performance of MoS₂electrodes.The lithium ion intercalation method uses the interaction between electrodes and electrolytes to make lithium ions enter into layered MoS₂ and change the microstructure of layered MoS₂,thus improving the electrochemical performance of MoS₂.MoS₂ has a suitable adsorption and desorption capacity for hydrogen ions.Theoretically,it is a good catalyst for electrocatalytic hydrogen evolution.Layered MoS₂ can provide more adsorption space for ions in electrolyte and help ion transport between layers.The binding ability of MoS₂ with various substrates also makes MoS₂ stable on the substrates.After repeated cyclic stability tests,MoS₂ still exhibited excellent hydrogen evolution performance and capacitance performance.In the experiment,different intercalation conditions were changed to adjust the intercalation degree of lithium ion on layered MoS₂.The intercalation samples were characterized,hydrogen evolution performance and capacitance performance were tested.The best intercalation conditions for vertical MoS₂ samples grown on glassy carbon substrates by CVD method were obtained.