Synthesis And Properties Of MOFs-Derived Electrochemical Functional Materials

Renewable energy sources,such as solar and wind power,are taking up a growing portion of total energy consumption of human society.Owing to the intermittent and fluctuating power output of these energy sources,electrochemical energy storage and conversion technologies are playing key roles toward efficient and sustainable energy utilization.The design of electrode materials is the key to the practical application of electrochemical energy storage and conversion technology.As a relatively young but quickly growing family of porous materials,metal-organic frameworks（MOFs）have generated a tremendous amount of interest from researchers in widespread area.MOFs containing fully accessible redox-active metal centers and easily tunable pore structures have been successfully demonstrated as electrode materials for electrochemical devices.However,the insufficient electronic conductivity and chemical stability of most pristine MOFs limit the widespread application in energy-related devices.To overcome above limitations,in this present work,we choose a top-down strategy to convert MOFsprecursor into metal compounds and carbonaceous composites,and finally study their sodium-storage performance and bifunctional oxygen electrocatalysis performance,respectively.The details are listed as following:（1）We reported a novel two-time-sulfidation-in-cube strategy coupled with a facial selective etching method to insitu fabricate hollow microcube framework constructed by in-plane-parallel ultrathin MOS2 nanosheets（HMF-MOS2）using Zn,Mo-based hybrid zeolitic imidazolate frameworks（HZIF-Zn,/Mo）.The evolution of the hollow interior in this system is different with previous reports.And time-dependent experiments were carried out to monitor the formation process of the hollow structure.It has been found that the hollow interior is ascribed to the different diffusion rates ions.Then,the electrochemical properties of the as-prepared HMF-MOS2 were evaluated as an anode material for sodium-ion batteries（SIBs）and as a control experiment,pristine MOS2 synthesized at a traditional hydrothermal method was also tested for comparsion.The long cycling stability of HMF-MOS2 electrode was performed at a current density of 0.1 A g-1,in particular,it delivers a high capacity of 510 mAh g-1 at 100 mA g-1 after 100 cycles.（2）Co₉S₈ nanoparticle anchored on N,S co-implanted three-dimensional carbon matrix is synthesized by a simultaneous carbonization and sulfidation of zeolitic imidazolate frameworks（ZIFs）strategy.The obtained Co₉S₈@NSCM catalyst exhibits high activity and stability in bifunctional oxygen electrocatalysis.In addition,by confining Co9Sg NPs into N,S co-implanted carbon matrix,corrosion and aggregation can be effectively prevented,and thus the Co₉S₈@NSCM catalyst exhibits excellent cycling stability in Zn-air batteries.