Design,synthesis And Performance Exploration Of 2D Covalent Organic Frameworks Based On Thiophene Structure

With the rapid development of science and technology,people are looking forward to new chemical materials with the rapid progress of productivity.Under this background,covalent organic frameworks(COF)come into being.Since the world's first case of COF came out in 2005,more and more chemical workers have focused on it.So far,the field of COF has ushered in the spring of vigorous development.Covalent organic frameworks(COF),as its name suggests,is a porous crystalline material connected by stable covalent bonds.COF often has a series of advantages,such as high specific surface area,adjustable pore size and unique molecular structure.So far,after more than ten years of development,the synthesis of COFs with various bond types and topologies has been developed and designed by many chemists,and the application design of COFs is also very wide.For example,they have long been used in gas adsorption and separation,photoelectron,heterogeneous catalysis and other applications.Here,we hope to realize the efficient catalysis of redox reaction(ORR)through the diversity and performance advantages of COF,so as to contribute to the practical application of COF.The summary is as follows: in this paper,the author designed and synthesized two two-dimensional COFs containing thiophene groups——JUC-607 and JUC-608,and explored their functionalization on this basis.This paper divides the work into the following two parts:The second chapter of this paper mainly talks about the design basis and synthesis process of two-dimensional COF,JUC-607 and JUC-608.They are based on the Schiff condensation reaction between TAPT or TTBA with BTT as the reaction mechanism and combined with the [C3 + C3] building blocks,and both COFs are hcb topology with hexagonal structure and AA stacking mode.Further,through a series of characterization experiments including PXRD,FT-IR and nitrogen adsorption/desorption,we confirm that the two-dimensional COFS designed and synthesized by us,JUC-607 and JUC-608 are the things what we preliminary design,and meanswhile they have a series of advantages such as large specific surface area and high crystallinity,which lays a solid foundation for our next functional exploration.The third chapter of this paper mainly discusses the functionalization of two-dimensional COF,JUC-607 and JUC-608,mainly to achieve high-efficiency catalytic performance in oxygen redox reaction(ORR).Based on the thiophene containing structure,that is,the special structure containing heteroatoms,we judge that the two-dimensional COFs of JUC-607 and JUC-608 will show good ability in the catalytic activity of ORR.Therefore,we have done a series of experiments to confirm this conjecture.We test these two COFs in 0.1 mol / L oxygen saturated KOH electrolyte,and we take a series of electrochemical related property tests such as LSV curve,CV Curve,onest potential,half-wave potential and so on,and the results are pretty well.We can conclude that these two COFs with thiophene structure have a good prospect in ORR catalysis.To sum up,we first design and synthesize two two-dimensional COFs containing thiophene structure,and further explore their functionalization in ORR catalysis,and both of them show good performance.In particular,JUC-608,with its larger pore size which is more helpful to the electron conduction ability show a better ORR catalysis ability than JUC-607.