Controllable Synthesis And Electrochemical Characterization Of Mo-Based Ternary Alloy Compounds

With the increasing demand of people and the growth of social economy,the demand for energy have gradually increased.And now were still using more fossil energy,which inevitably causes environmental pollution and energy waste.To solve these problems,the key lies in the development of a safe,clean and sustainable energy storage system.Lithium-ion batteries(LIBs)and electrochemical hydrogen evolution reaction(HER)are widely used and studied for energy conversion.Lithium-ion batteries have the advantages of high-capacity storage,high capacity retention,and low cost.In the same way,hydrogen energy is the clean energy with the greatest potential for development in the 21 st century,and a great deal of development will greatly ease the energy crisis facing now.This dissertation aims at the existing electrode material and electrocatalyst problems,designs and hydrothermally synthesizes some Mo-based ternary metal materials for LIBs and HER.The main research contents are as follows:(1)A one-step hydrothermal synthesis method was used to prepare different structures of ZnMOS4 nanomaterials,including nanospheres and hollow nanosphere.After a series of characterizations,the properties such as morphology,crystal shape,porosity,and elemental composition of the material were obtained.This is the first systematic analysis of the complete physical properties of ZnMoS4.Using ZnMOS4 as the anode in LIBs,the intrinsic initial discharge capacities of the two materials were found to be 877.2 and 819 mA h g-1,respectively.The first Coulomb efficiency reached more than 90%,and it also had a good rate performance.ZnMoS4 nanomaterials have a large specific surface area and provide many active sites,greatly increasing the electron transport and cycling performance in LIBs.(2)In-situ hydrothermal synthetize ZnS/MoS2-DETA organic-inorganic hybrid structure,calcined under nitrogen to obtain ZnS/MoS2/C heterostructure material.Through XRD,SEM,TEM and other tests,it was found that the product was composed of inner urchin-like MoS2 flower-like nanosphere,external ZnS nanoparticles,and carbon structures flooded between the layers.The initial discharge capacity of the anode material reached 1063.1 mA h g-1,the first Coulomb efficiency was 87%,and the following cycle was more than 98%.It can be seen that the formation of heterostructures does enhance the carrier transport and charge-discharge capacity.(3)Two kinds of CoMoO4 nano-film structures based on foam Ni were hydrothermally synthesized,and then the CoMoS4 clustered nanoroad and hollow nanosheet were obtained through one-step vulcanization process.In HER,the hydrogen overpotentials of CoMOS4 nanorods and hollow nanosheets were 175 and 170 mV,respectively.The oxygen overpotentials were 0.364 and 0.321 V,respectively,and the CoMOS4 hollow nanosheets had good electricity.chemical stability.When CoMOS4 hollow nanosheet were used for two-electrode experiments,good results were also obtained.Amorphous and dense mesh-like film structure greatly increases the electron transport,the increase of active sites and the degree of exposure.