The Research Of Calcination Strategy Of MOF Precursors And MOF-derived Carbon-based Materials In Supercapacitors

Metal-organic frameworks（MOFs）,as a new class of porous materials,have been focused by many material scientists,which attributes to plentiful advantages（such as highly ordered architectures,large specific surfaces and tunable pore sizes）.Moreover,the metal ion and organic ingredient of MOFs can be regarded as metal and carbon resources,respectively.Thus,the unique morphology,highly dispersed and large porosity carbon-based materials have been successfully prepared,through the calcination-thermolysis of MOFs in insert atmosphere.Furthermore,MOF-derived carbon-based materials possess considerable attention in many applications such as optical,magnetic,electrocatalysis and supercapacitors.However,there is a key issue about how to synthesize the desired MOF-derived matierals by utilizing the rational MOFs,considering this“huge resource”with various constitutions and unpredictable architectures.It is highly necessary to exploit conventional principles for the artificially controllable syntheses of MOF-derived carbon-based materials.On account of above-metioned ideas,in this thesis,we emphatically perform the systematic researches on the relationships between factors（the metal ion,conterion and lattice dimension of MOFs）and characteristics of MOF-derived carbon-based materials.The main contents have been summarized as following:1.A novel Cu-MOF including the explosive ClO₄^-ion was successfully synthesized via tube-diffusion process.Cu-MOF exhibits a 3-fold interpenetrating diamondoid net based on the square-planar Cu^IInode,which still possesses the 1D hexagonal channel resided by ClO₄^-ion.Importantly,a series of Cu@C composites were prepared by calcination of Cu-MOF and a sequence of hierarchically flower-like N-doped porous carbon materials（NPCs）were further afford through the acid treatment.After the intensive and careful analysis,it is found that the 1D primitive channel,perchlorate ion and as-synthesized copper particle have prominent pore-forming effects.Expecially,the ClO₄^-ion could induce the abundant pores on the carbon substrate,which was firstly found by our group as the explosive pore-forming effect.Significantly,NPC-900,showing the best porous features and largest specific capacitance(the remarkable specific capacitance is 149 F g^-1at the current density of 0.5 A g^-1).2.A sequence of Co-MOFs 1-3 with similar ingredients have been synthesized,which based on the 1,4-bis（imidazol-1-yl）benzene（bib）as the auxiliary ligand and three structure-relatedaromaticacids（1,2-benzenedicarboxylicacid=o-bdc,1,3-benzenedicarboxylic acid=m-bdc,and 1,4-benzenedicarboxylic acid=p-bdc）as primary ligands.Two series of composites（Co@CNTs and CoS₂@CNTs）were successively fabraicated through the calcination-thermolysis and in situ gas-sulfurization processes,respectively.It is found that the Co species from parent MOFs possesses the highly catalytic graphitization of carbon at the high temperature.Moreover,in situ gas-sulfurization method could remain the similar morphologies of CoS₂@CNTs without destroying previous evenly dispersed and high graphitization structures.Topology and Brunauer-Emmett-Teller（BET）analyses elucidate that the bdc^2-ion could control the pore diameter of MOF-derived carbon composite by adjusting the lattice dimension of Co-MOF.Meanwhile,the electrochemical properties of CoS₂@CNT electrode were intensively investigated and（p）-CoS₂@CNT shows the outstanding supercapacitance performance as the potential electrode material.