Controllable Synthesis And Properties Of Metalorganic Frame Work Swith Hierarchical Pores

Metal-organic frameworks?MOFs?have attracted a lot of attention for a long time because of theirabundant changes in framework structure and potential applications in gas storage and separation,chemical sensing,heterogeneous catalysis and drug delivery,etc.In recent years,the research focus of metal-organic frameworks has transferred into obtaining different hierarchical pore structures in MOFs.The formation of hierarchical pore in MOFs can afford extremely exquisite pore structure that endows MOFs materials with many fascinating properties.At present the main route of obtaining hierarchical pores is introducing large pores into microporous structures of MOFs,such as template-assisted synthesis,post-synthetic modification,perturbation-assisted nano-fusion synthesis,hydrolytic transformation and plasma etching process,etc.But among these strategies,most need harsh experimental conditions and tedious subsequent treatment,and most of the obtained hierarchical structures exhibited irregular pore structure which constructed by disorder accumulation of particles and showed disordered pore distribution,while the hierarchical framework with regular ordered pores is rare.So it is highly desirable to develop a simple and reliable method to produce well-ordered hierarchical-porous MOFs.This paper has carried out the following works:?1?The controllable synthesis,characterization and properties of hierarchical Cu-TATAB metal-organic framework.The ordered hierarchical Cu-TATAB framework?named as MM-CuTATAB?was synthesized through a facile in-situ self-assembly by the reaction of Cu²⁺ with the ligand of H3TATAB?H3TATAB:4,4',4”-s-Triazine-1,3,5-triyltri-p-aminobenzoic Acid?in DMF and characterized by scanning electron microscopy?SEM?,transmission electron microscopy?TEM?,X-ray powder diffraction,field emission scanning electron microscopy?FE-SEM?,etc.The results show that the obtained framework was constructed by hierarchical pore structure of mesopores?37.3 nm?and macropores?55.2nm?.The tests on the influencing factors of hierarchical pores formation and the stability of MM-CuTATAB in different solvents exhibited the amount of H2O2 and the reaction time are key factors for the formation of hierarchical pore structure and MM-CuTATAB shows good stabilities in some organic solvents such as CH3 OH,C2H5OH and CH2Cl2 andpoor stabilities in H2 O,HCl and NaOH.The adsorptiontest to CO2 showed thatMM-CuTATAB could adsorb1.18mmol/gand 0.7mmol/g CO2 at 273K and 298 K respectively.?2?The synthesis,characterization and ORR properties of hierarchical Cu/M-TATAB which constructed by Zn²⁺,Co²⁺ and Ni²⁺-doping into MM-CuTATAB..With adding different amount of Zn²⁺,Co²⁺ and Ni²⁺in the reaction mixture,Zn²⁺,Co²⁺ and Ni²⁺-doped MM-CuTATAB were synthesized and characterized.It showed that the obtained bi-or tri-metal MOF maintained the network hierarchical framework in MM-CuTATAB.Then the carbonized products in different temperature of Zn²⁺,Co²⁺ and Ni²⁺-doped MM-CuTATAB were obtained and their electrocatalytic properties for oxygen reduction were tested.The results show the optimal carbonization temperature is 700? for Zn²⁺-doped MM-CuTATABwith the mole ratio of Cu²⁺ to Zn²⁺ is 3:1,800 ? for Co²⁺-doped MM-CuTATABwith the mole ratio of Cu²⁺ to Co²⁺ is 4:1,700? for Ni²⁺-doped MM-CuTATABwith the mole ratio of Cu²⁺ to Ni²⁺ is 5:1,and 700? for Zn²⁺/Co²⁺-doped MM-CuTATABwith the mole ratio of Cu²⁺: Zn²⁺: Co²⁺ is2:2:2.?3?The synthesis,characterization and dye adsorption properties of fiower-like Zn-TATAB framework.Flower-like Zn-TATAB framework?named F-ZnTATAB?was synthesized by the reaction of zinc nitrate with H3 TATAB in DMF in solvothermal condition.Characterized by SEM,TEM,PXRD and FE-SEM,the flower-like structure is constructed by nanoflake of Zn-TATAB.The tests on dye-adsorption properties showed that F-ZnTATAB can absorb methylene blue?MB?and malachite green?MG?with the efficiency of 82.57%,83.23% in 5min respectively,which make them become a kind promising adsorbent for controlling dye pollution.