Synthesis And Application Of Three-Dimensional Covalent Organic Skeletion Structure Based On Spirobifluorene

This paper designs a new three-dimensional COFs building unit,tetraaminebased spirobifluorene,and synthesizes three new types of COFs.It is the first time that COFs are applied in the field of perovskite solar cells,and the conversion efficiency is significantly improved.Bipyridine was introduced into the framework of snail COFs,and palladium metal nanoparticles were supported to obtain a highly efficient and recyclable heterogeneous catalyst.The paper mainly includes the following parts:In the first chapter,we outline the history of the development of porous materials,which leads to the organic framework of porous organic materials with good crystallinity.The principles of structural design,synthesis methods,application fields,major problems and direction of development future issues are introduced in detail.In the second chapter,we introduce the star material tetraamine-based spirobifluorene in the field of perovskite solar cells into the structure of COFs,and based on the published papers,the yield of tetraamine-based spirobifluorene is improved.The dehydration condensation reaction synthesizes tetraamine-based spirobifluorene with terephthalaldehyde and biphenyldialdehyde in a Pyrex tube under vacuum to synthesize SP-3D-COF 1 and SP-3D-COF 2.The chemical structure was confirmed by infrared characterization,solid nuclear magnetic,and other techniques.The crystal structure was analyzed by powder XRD and computer simulation.The microstructure of COFs can be visualized by scanning electron microscopy and transmission electron microscopy.Finally,the application of two materials in the field of nitrogen adsorption and perovskite solar cells was studied.Studies have shown that both COFs have higher specific surface area and can significantly improve the conversion efficiency of solar cells.PCE has increased by 30%,which is a very rare result in the field of solar cells.In the third chapter,based on the work of the second part,we find that the COFs constructed by the spirobifluorene have very common three-dimensional pores.We consider this to be modified in the pores and introduce a bipyridyl structure with coordination function.Then,we introduced the catalytically functional palladium nanoparticles into a covalent organic framework.We found that the palladium nanoparticles were uniformly dispersed in the COFs framework by a transmission electron microscope,and the particle size was about 1.3 nm.We will use the heterogeneous catalyst obtained for the Suzuki-Miyaura coupling reaction.The experimental results show that the heterogeneous catalyst can convert more than 95% under relatively mild reaction conditions and can be recycled many times.The fourth chapter summarizes the full text and looks forward to the future development direction.