Interface Preparation And Properties Of Two-dimensional Graphdiyne Materials

Graphdiyne(GDY)is a two-dimensional material with a single atomic layer thickness constructed from sp and sp~2 carbon atoms according to a certain period.As an emerging artificially synthesized carbon material,graphdiyne has rich carbon chemical bonds,unique electronic structure,uniform pores and a highπ-conjugated framework,which make it apply to semiconductor devices,catalysis,gas separation,biomedicine,and energy storage and other fields.Meanwhile they explored many effective doping modification methods through various post-processing methods and the design of precursors.So far,achieving tunable properties of GDY materials with ideal doping structures and unique morphologies through a simple method remains a huge challenge.At the same time,that is also a major scientific issue that we faced.In this article,we are mainly based on the synthesis concept of graphdiyne and the polymerization process of liquid-liquid and solid-liquid interface to realize the preparation of graphdiyne films,and the functional groups and functional parts are introduced into the precursor to achieve precision doping of the graphdiyne.The two-dimensional polymer can be accurately doped through the precise doping concept of"bottom-to-top",and the precise doping two-dimensional polymer can be further explored in the fields of catalysis and fluorescence et.al.This article will state from the following aspects:The first work,a bottom-up synthesis of 2D carbon Cyano-graphdiyne(CN-GDY)was reported.We completed the structural design replacing separated three alkynyl groups on the benzene ring with three highly electron-withdrawing cyano groups,and used the cyano group of the classic electron-withdrawing group to accurately dope the graphyne without sacrificing the regularity of the xy axis and stability.The cyano group effectively affects the electronic properties and other required physical or chemical properties of graphyne.The highly crystalline polymerization process was completed at the liquid-liquid interface through the Glaser-Hay coupling reaction of the alkyne bond.Meanwhile,we verified the optimization results on the energy band and electronic structure.The second one,we linked the tetraphenylethene(TPE),alkyne bond,and Glaser-Hay coupling reaction on the surface of copper foil,and we constructed a long-range ordered crystal structure of a tetraphenylethene fluorescent film with tetrastyrene as the core building block for diacetylene linker.The tetraphenylethene with unique aggregation-induced luminescence(AIE)behaviour developed and synthesized film with a well-defined structure,and the obtained polymer has the characteristics of an ultra-thin large area and a fluorescent film with a certain crystal state.The pore structure and fluorescence performance of films were validated by TEM,SEM,fluorescence spectroscopy and Raman spectroscopy.Finally,we further designed a new precursor on the basis of the third chapter’s precursor.We extend the molecular distance of the imine bond to the core TPE molecule with the rigidity and conjugation of the alkynyl group to achieve the purpose of limiting charge transfer,so as to achieve maintenance of fluorescence performance.The single-layer fluorescent two-dimensional polymer containing both TPE and imine bonds was obtained at the air-water interface with Langmuir-Blodgett method.The obtained single-layer imine-linked chemical structure was analyzed by the tip-enhanced Raman spectroscopy(TERS).The nanostructures and fluorescent property of 2DP films were characterized by optical microscopy,SEM,TEM,AFM and fluorescence spectrum.