The Preparation Of Functional Zirconium-Based Metal-Organic Frameworks Materials And Electroanalytie Application

Metal-organic frameworks（MOFs）,which consist of metal ions/clusters connected by organic ligands through self-assembly,is recently a hot spot in the field of new functional materials.MOFs as a novel 3D coordination compounds with the characteristics of both organic polymers and inorganic compounds,they possess many unique properties,such as permanent porosity,larger specific surface area,good thermal stability,tailorable pore size and chemistry and so on.However,due to its intrinsic weaker electronic conductivity and electrochemical stability,the electrochemical applications of MOFs exist certain limitation.Based on the above considerations,precise chemical modification can not only improve the deficiency of MOFs,but also endow MOFs special function,which extends the application of MOFs in the field of electrochemistry.In this paper,Zr-MOFs as the basic material were functionalized by carbon nanomaterials and metal nanoparticles,respectively,Zr-MOFs/carbon and M@Zr-MOFs composites were prepared.We adopted various methods to characterize as-prepared materials.The electrochemical properties of Zr-MOFs/carbon nanocomposites were studied by simultaneous detection of dihydroxybenzene isomers（DBIs）.In addition,hydrazine（N₂H₄）is chosen as probe molecules to investigate the influence of the carrier structure on the electrocatalytic performances of M@Zr-MOFs composites.The main contents mentioned in this dissertation are summarized as follows:1.Zr-MOFs/mesoporous carbon composites（UiO-66/MC）have been synthesized with a simple hydrothermal method for the first time.Using this method,we have successfully prepared UiO-66/MC composites with different amount of MC.The excellent properties of UiO-66 and MC could endow the UiO-66/MC composites with good electrochemical performances.The UiO-66/MC material not only possesses excellent electrochemical stability,but also has a larger pore size and a good conductivity.Therefore,the composite is utilized as novel electrode material for the simultaneous and sensitive determination of DBIs.Under the optimized conditions,electrochemical tests indicate that the UiO-66/MC-3 exhibits outstanding electrocatalytic properties,such as a larger peak potential difference,higher sensitivity,wider linear range,good electrochemical stability and excellent anti-interference ability.In addition,the sensor also realizes DBIs detection in actual water samples.2.Encapsulation of Pt NPs into Zr-MOFs（Pt@UiO-66/67/68）were prepared by simple and convenient one-step ethanol thermal reduction method.The amount of Pt NPs have been optimized to obtain the highest catalytic ability.Additionally,the microstructure and electrochemical properties of composites were systematically characterized,and the influence of the carrier structure on the electrocatalytic properties of composites were studied in detail.The study found that the Pt@UiO-66/67/68 composites display different reaction mechanism and electrocatalytic performances for electro-oxidation N₂H₄.Pt@UiO-66-2 shows the best electrocatalyticperformances.These findings may help to understand structure-performance-catalytic mechanism relationships of MOF-based composites.