Synthesis And Catalytic Application Of Intermediate Conversion Routes Of One-dimensional ZIF And Its Derivative Materials

The rapid development of the industry has accelerated the progress of society,but also brought a series of problems in environmental pollution and energy shortage.The development of effective materials for environmental governance and energy conversion has attracted worldwide attention.As the most representative metal organic framework,ZIF-8 possesses rich pore structures and large specific surface area,which is a good adsorption material.At the same time,because it contains both organic ligands and metal components,it is also a suitable precursor for the synthesis of carbon-based energy storage and catalytic materials.The development of effective methods for the preparation of ZIF-8-based materials in large quantities is the key for its application in practice.Based on above analyses,the contents in this thesis include following aspects:First,we developed a precursor(intermediate)conversion route to realize the large-scale preparation of ZIF-8 with a tubular structure.Traditional ZIF-8 is mainly obtained by the direct precipitation reaction of soluble zinc salt and ligand in solution.The yield of obtained ZIF-8 is relatively low and the morphology is manly polyhedron.We used a one-dimensional zinc-ethylene glycol complex as a precursor to control the reaction rate of 2-methylimidazole with zinc ions.Finally,a tubular ZIF-8 can be formed in DMF(N,N-dimethylformamide)solvent.It has a special tubular shape and high output.By combining with sponge,it can be used as a stable water-oil separation material and possesses better adsorption capacity than that of polyhedron ZIF-8.ZIF-8 synthesized by the precursor conversion route possesses special tubular structures and high yield,which is beneficial to its practical application.The2-methylimidazole in ZIF-8 is a potential carbon source.Thus,the nitrogen-doped carbon can be obtained by pyrolysis of T-ZIF-8,which can be used as an energy storage and catalytic material.The tubular N-doped carbon can be used as the electrode material of supercapacitors with high capacitance and good stability.ZIF-67(cobalt coordinating with 2-methylimidazole)is isomorphic of ZIF-8,which can grow on ZIF-8 to obtain a composite structure.After pyrolysis,cobalt-based catalytic materials can be obained for electrocatalytic water splitting and other fields.We used the tubular ZIF-8 as a template to grown ZIF-67,and a tubular ZIF-8@ZIF-67 materials can be finally formed.By adjusting the heat treatment parameters,the CoP/nitrogen-doped porous carbon materials embedded in carbon nanotubes are obtained,which have good performance for water splitting.