Preparation Of 2D Nickel And Cobalt MOFs And Study Of Their Electrochemical Catalysis And Energy Storage

The energy shortage and environmental degradation are two of serious issues facing the world today.Excessive use of fossil fuels not only causes air pollution,but also makes global warming even more severe.As a result,scientists around the world are focused on developing and using clean,efficient,and sustainable new energy sources to replace fossil fuels.Metal-Organic Frameworks?MOFs?,one of the frontiers of popular base materials,provide important material support for many industrial products.Due to its high porosity,large specific surface area,and good structure and stability,MOFs have been widely studied and applied in the fields of gas separation,electrochemical catalysis,energy storage and biomedicine.Compared to three-dimensional?3D MOFs?crystals with ordered large pores,two-dimensional MOF?2D MOFs?nanosheets have thinner thickness,larger specific surface area,faster mass transfer rate and better electron transfer ability,which are effective strategies for the development of high performance electrocatalytic materials.At present,a variety of methods have been developed to prepare 2D MOFs,which can be divided into bottom-up and top-down synthesis methods.?1?Ultrathinning metal–organic framework nanosheets?Co-UMOF,NiCo-UMOF,Ni-UMOF?were synthesized by chemical synthesis.FT-IR,Thermal gravimetric,Scanning electron microscopy,Atomic force microscopy and X-ray diffraction were usd to characterize the MOFs.These materials are used to construct H₂O₂ sensing under different oxidation potentials was studied by cyclic voltammetry and chronoamperometry in KOH solution.The Co-UMOF exhibited excellent H₂O₂ oxidation and detection performance including a wide linear range from 0.5?M to 832.5?M,low detection limit of 0.69?M,and very fast sensing response in basic solution.By taking advantage of excellent conductivity,the Co-UMOF showed the low oxidation potential for H₂O₂ and good detection performance at 0.25 V.It was comparable to most carbon materials and reported MOFs materials for H₂O₂ detection.?2?The MOF/EG composite is synthesized under the condition of room temperature through a simple and economical method.The graphene material is prepared by using electrolytic graphite paper,the graphene is sonicated in DMF,and then the MOF/EG composite material?named Co-MoF/EG,NiCo-MOF/EG,Ni-MOF/EG?is synthesized by a chemical synthesis method.The material was characterized by XRD,Raman,SEM and TEM.The graphene composite Co,Ni and NiCo-based two-dimensional MOFs in the KOH solution as the non-enzymatic glucose under different oxidation potential was studied by the cyclic voltammetry and the time-current method.As the electrode material of the non-enzyme glucose sensor,the Co-MOF/EG has high electrocatalytic activity on the oxidation of the glucose,has high electrocatalytic activity.The linear range of 1?M to 3330?M,and detection limit of 0.58?M.The detection response to glucose in the alkaline solution is very fast.Most importantly,the stability and conductivity of the Co-MOF/EG are much higher than that of Ni-MOF/EG and NiCo-MOF/EG.The composite nanostructure utilizes high porosity and excellent electrical conductivity,which indicates that the coordination unsaturated metal atom is the main active center of electrocatalytic glucose.?3?Simple chemical synthesis of metal organic frameworks?Co-MOF,NiCo-MOF,Ni-MOF?is used as a high-performance LIB anode material.The results show that Li⁺are intercalated to the carboxyl groups and benzene rings of this MOF during cycling,accompanied by the distortion of octahedral sites.Furthermore,the MOFs employing this organic-moiety-dominated intercalation/deintercalation mechanism exhibits nprecedented long-term cyclic stability.The Co-MOF,NiCo-MOF,and Ni-MOF materials provide lithium ion storage capacities of 847,516 and 189 mAh g^-1,respectively,at 100 current cycles at 100mA g^-1.The MOFs materials improved electrical conductivity and reduce volumetric changes during charge-discharge,maintaining structural integrity.