Metal Organic Framework/Two-dimensional Carbon-derived Materials:Catalytic Performance Study

Owing to the aesthetically pleasing porous structure and high surface area,Metal-organic frameworks?MOFs?exhibit potential applications in adsorption,separation,catalysis,luminescence,magnetism and energy storage.The latest two decades have witnessed a surge of research,resulting in mature synthetic strategy and structure-function relation.In the vein,MOFs-derived composite material not only feature the structural property of MOFs but also generate unique physical chemical property,such surface-interface effect.Thus,it has gradually attracted more interest because of unclear assemble laws and structure-function relation.In view of such situations,this thesis firstly designs new-type MOFs as footstone,and further investigate synthetic strategy and catalytic property of MOFs/2D carbon composite.First,we reported the synthesis and property of H₃BTB ligand –based MOF.Single crystal-structure analysis demonstrates that it features three-dimensional?10,3?net anionic framework with the encapsulation of neutral DMF molecules and H₂NMe²⁺ in this channel along b axis.By emission property measurement,it is found that emission peak of 361 nm more blue shifts than that of H₃BTB ligand?396 nm?,associating with the destroyed?-type bond of H₃BTB.More interestingly,alternating current impedance measurements reveal an unusual temperature-dependent conductance,largely induced by the transmission of H₂NMe²⁺ ions in the channel.Secondly,designed assemble of catalytic property of Co₃O₄/COF were subsequently identified.Via the chemical modification,benzoic acid was connected with the surface of COFs.Through the reaction of modified COFs,metal and ligand,the ZIF-67/COFs composite material were obtained.Further calcined under the inert atmosphere,the ZIF-67/COFs were converted into Co₃O₄/COF composite,where highly dispersed Co₃O₄ particles were uniformly load on COFs.Electrochemical performance test uncover that such composites feature oxygen evolution reaction catalytic performance,comparable to commercial Pt/C.Lithium ion battery performance measurements also reveals that such composites possess good reversible capacity,cycle performance and rate performance.By a series of characterization and comparisons,we verified that these property is largely related with the synergetic effect of porous structure of COFs and Co₃O₄ nanoparticle.Finally,graphene,serving as support,was used to investigate the effect of support on catalytic property.To this end,we also modified graphene oxide by using of 5-NH₂-isophthalic acid,and further reacts with isophthalic acid and metals under the condition of ionic liquid,resulting in MOFs/graphene composite.Subsequently,the uniformly distributed CoNiOx/graphene composite with 15 nm nanoparticles were achieved by the high-temperatur calcination.Electrochemical characterization demonstrates that the material features a certain property of hydrogen evolution reaction?HER?and oxygen reduction reaction?ORR?.Summary,it is concluded that: 1)Post modification of carboxylate functional group can promote the 2D carbon load MOF.2)Via high-temperature calcination,supporting MOFs can be effectively transformed to highly uniformly metal-oxide nanoparticle with high electrochemical properties.