Controlable Synthesis Of MoS₂ Nanoflowers And MoS₂/CNTs Nanocomposites For The Application Of Supercapacitor

Due to the successful research and extensive application of graphene,the layered two-dimensional materials with graphene-like structure begin to attract researchers'attention.Among them,the Molybdenum disulfide?MoS₂?has attracted attention due to the unique "sandwich" sandwich structure and excellent physical-chemical properties.MoS₂ has broad application in the supercapacitor and lithium-ion battery storage fields.The synthesis of MoS₂ is basically divided into physical and chemical methods,Hydrothermal method as a one of important chemical methods is broadly used in the synthesis of MoS₂ nanosheets or nanoflakes.It is because excellent yield and high purity of products are easier to achieved by this method.In this thesis a large number of MoS₂ nanoflowers with large specific surface area were synthesized by hydrothermal method and the supercapacitor prepared by synthesized materials showed good electrochemical performance due to large specific surface area morphology of the nanoflowers.In order to improve the conductivity and cycle testing stability of MoS₂ nanoflowers,we mixed graphited carbon nanotubes?CNTs?with MoS₂ nanoflowers to prepare the composites of MoS₂ and graphite carbon nanotubes.The obtained MoS₂-CNTs composites demonstrated enhanced cycle testing stability and lower resistance during electrochemical test.The main contentss and conclusions of this thesis are as follows:?1?The whole preparation process of MoS₂ nanoflowers and the electrochemical measurement of the regarding supercapacitors.First,we synthesized MoO₃ nanoribbons with a diameter of about 200nm by hydrothermal method,and then we use the obtained MoO₃ nanoribbons as a react reagent mixed with thiourea to synthesis MoS₂ nanoflowers by hydrothermal method again.The morphology of MoS₂ nanoflowers was controlled by changing the reaction temperature.Moreover,we prepared supercapacitors using the synthesized MoS₂ nanoflowers as electrode materials and measure the devices electrochemical performance.The measurement results showed that the specific capacitance of the sample of MOS2-240 was 932 Fg-1 when the voltage window was 0?0.65V and the electrolyte solution was 1M KOH and a current density of 2 Ag-1.It also showed that the specific capacity can maintain 78%after 1000 cycles charge and discharge test.?2?The synthesis of MoS₂?nanoflowers?/CNTs composites using synthesized MoO₃ nanoribbons and thiourea and CNTs under hydrothermal conditions.The morphology of MoS₂/CNTs composites was controlled by tuning the amounts of graphitized CNTs.The electrochemical measurement of the composites showed that the specific capacitance of the samples was 759 Fg-1 when the voltage window was 0?0.6V and the electrolyte solution was 1M KOH and a current density of 2 Ag-1.The power density and energy density of MoS₂/CNTs composites were 136.6 WhKg-1 and 2698 WKg-1,respectively.They were better than pure MoS₂.It also showed that the specific capacity can maintain 91.7%after 2000 cycles charge and discharge test.