Application Research Of MOFs-derived Multi-metal Sulfide Materials In The Field Of Electrochemistr

At present,the optimal electrocatalysts for electrochemical sensing and electrocatalytic water decomposition are Pt based materials and Ru or Ir oxides.However,their scarce resources and high costs limit their application.Metal organic frameworks（MOFs）based composite materials and derivatives have been widely used in the fields of electrochemical sensing and electrocatalytic water decomposition due to their high specific surface area and porosity.This article synthesized transition metal sulfide materials using MOFs based materials as precursors,combined with the synergistic advantages of multiple metals,and demonstrated their excellent electrocatalytic performance through electrochemical sensing and electrocatalytic water decomposition.The main work includes:In this section,ZnCo-MOF was used as a precursor to synthesize ZnCo₂S₄electrode material through hydrothermal synthesis,and it was applied to electrocatalytic oxidation of glucose.Compared withCo S and Zn S,ZnCo₂S₄ showed better electrocatalytic oxidation performance of glucose,with a detection limit as low as 0.007μM.And with 3μM-9μM and 10μM-0.1 m M.The detection range of and the research on the electrocatalytic mechanism of ZnCo₂S₄ found that the advantages of ZnCo-MOF material with large specific surface area and more active site combined with the synergistic effect between Zn andCo led to the excellent electrocatalytic oxidation performance of ZnCo₂S₄ material for glucose.In this part,in order to solve the influence of binder in the process of making electrodes from powder materials,NiCo-MOF is directly grown in situ on foam nickel,vulcanized intoCo-Ni₃S₄ material,and applied to electro catalytic reduction of hydrogen peroxide.Compared with undoped Ni₃S₄,Co doped Ni₃S₄ material shows better electro catalytic reduction of hydrogen peroxide performance,and its detection limit for hydrogen peroxide is as low as 1.96μM.And showed a linear relationship to hydrogen peroxide in the range of 0.02 m M-5 m M.TheCo-Ni₃S₄ material inherits the advantages of MOFs materials in the derivation process,and the doping ofCo also plays a key role.The mechanism study shows that the doping ofCo changes the electronic configuration of Ni₃S₄ material,andCo replaces a part of Ni on the electrode surface,which exposes more active site and accelerates the redox reaction on the electrode surface.This proves that NiCo-MOF@NF The derivedCo-Ni₃S₄material is an excellent electrochemical sensing material.In this part,in-situ growth was carried out on foam nickel ZnCo Ni-MOF@NF,and it was sulfurized into Zn-Co-Ni₃S₄ material through gas phase reaction,which was applied to electrocatalytic OER.The electrochemical analysis results show that compared to Zn-Ni₃S₄ andCo-Ni₃S₄ materials,the multi metal doped Zn-Co-Ni₃S₄material exhibits better electrocatalytic OER performance,with an over potential of only 297 m V and a Tafel slope of 122 m V dec^-1 at a current density of 50 m A cm^-2.On the research surface of electrocatalysis mechanism,the addition of Zn greatly reduced the resistance of the material and accelerated the electron transfer rate of the electrocatalytic OER.The addition of Zn also changed the electronic configuration of the material,making the surface of the electrode material leak more active site,and accelerating the oxygen precipitation reaction of water on the electrode surface.In addition,vapor phase vulcanization removes organic groups from MOFs while avoiding water damage to the structure of MOFs.The results show that,ZnCo Ni-MOF@NF The derived Zn-Co-Ni₃S₄ material has excellent electrocatalytic OER performance and is an excellent electrocatalyst.In this section,ultra-thin nanosheets of NiCo₂S₄ material were synthesized by hydrothermal vulcanization using NiCo-MOF as a precursor and applied to electrocatalytic HER.The morphology of NiCo-MOF was regulated through different preparation methods,and it was found that the ultra-thin layered morphology had the best electrocatalytic OER performance.After sulfurization treatment,NiCo₂S₄exhibited the best electrocatalytic OER performance compared to Ni S andCo S.At a current density of 10 m A cm^-2,its overpotential was only 33 m V,and the Tafel slope was 145 m V dec^-1.The mechanism study shows that the excellent electrocatalytic HER performance of NiCo₂S₄ material benefits from the advantages of the ultra-thin MOFs material with large specific surface area and more active site;The synergistic effect between Ni andCo is also a key factor in enhancing the electrocatalytic HER performance,that is,the redox reaction between Ni andCo accelerates the valence state transition between the two,accelerating the process of material electrocatalytic HER.The results indicate that the ultra-thin layer NiCo₂S₄ material derived from NiCo-MOF is an excellent electrocatalytic HER material.