Synthesis And Application Of Phenylamino-,Phenoxy-,and Benzenesulfenyl-Linked Covalent Triazine Frameworks

Covalent triazine frameworks（CTFs）are porous organic covalent polymers containing triazine rings.Due to their stable framework structure,high specific surface area and structural tunability characteristics,CTF has broad application prospects in the fields of storage and separation,energy storage and catalysis.Therefore,the development of new covalent triazine framework materials has become a hot research topic.In this paper,three covalent triazine framework materials were developed using three monomers containing triazine rings as the building unit.The gas adsorption and supercapacitor properties of the materials were studied.The main work includes the following two aspects:（1）Synthesis of monomers and triazine covalent framework materials.In this chapter,2,4,6-tris（4-cyanophenylamino）-1,3,5-triazine（TAT）,2,4,6-tris（4-cyanophenoxy）-1,3,5-triazine（TOT）,and 2,4,6-tris（4-cyanobenzenesulfenyl）-1,3,5-triazine（TST）was synthesized by nucleophilic substitution reaction.The structures of the three monomers were characterized and analyzed by means of characterization such as nuclear magnetic resonance,mass spectrometry and spectrum.Covalent triazine framework materials were synthesized by TAT,TOT and TST as building by cyano trimerization under catalysis of ZnCl₂.CTF-X₄（X=N,O,S）were synthesized by stepwise heating,which led the structure thermal stability,but the specific surface area is blew.Meanwhile,CTF-X₆ were synthesized bytwo-step high temperature polymerization method.However,the structure of CTF-X₆ has partially carbonizes during the polymerization process,therm At the same time,the structure,thermal stability,specific surface area and morphology of the material were analyzed.The results show that the covalent triazine framework materials（CTF-N₄,CTF-O₄,CTF-S₄）synthesized by temperature-programming method do not undergo partial pyrolysis during the polymerization process.The covalent triazine framework（CTF-N6,CTF-O6,CTF-S₆）structure obtained by two-step polymerization at 600 ^oC will be partially carbonized during the polymerization process.It has a higher specific surface area,the specific surface area of CTF-N₆ is 1236 m² g^-1,the pore volume is 0.51 cm³ g^-1,and the specific surface area of CTF-O₆ is 1748 m² g^-1.The pore volume is 0.84 cm³ g^-1;the specific surface area of CTF-S₆ is 1003 m² g^-1,and the pore volume is 0.46 cm³ g^-1.（2）Systematic study the gas adsorption and supercapacitor properties of covalent triazine framework materials.However,the systematic study of the relationship between PhNH-,PhO-,and PhS-linked CTFs and CO2 uptake performance has not yet been conducted.Gas adsorption and adsorption of synthetic covalent triazine framework materials（CTF-N₄,CTF-O₄,CTF-S₄）separation performance was explored and the CO2 adsorption capacity,CO2 adsorption heat and selective adsorption of CO₂/N₂ were systematically studied.The results show that CO₂ capture performances of such CTFs are confirmed to rely on the incorporated heteroatoms and increases in the order of PhNH->PhO->PhS-linkage in CTFs.Theoretical calculation demonstrates the same trend of the CO2 binding energies and are found to be 220.72kJ mol^-1,19.33 kJ mol^-1,and 13.48 kJ mol^-1,respectively,for PhNH-,PhO-,and PhS-bridged CTFs.However,The three covalent framework materials with high temperature polymerization at 600°C have higher CO₂ adsorption capacity,and the adsorption capacity of the material with the highest adsorption capacity is CTF-N₆ of 5.0 mmol g^-1（1 bar 273 K）.The carbon material N/C-1-800 was prepared by pyrolysis of CTF-N₅ at800°C.The performance of the supercapacitor was investigated:its capacitance value was 319 F g^-11 at a current density of 1 A g^-1,when the flow density is increased to 100A g^-1,the capacitance value is 234 F g^-1,the retention rate is 81%.