Study On The Chemical Synthesis Of New Graphydiynes

Graphdiyne（GDY）is a member of two-dimensional（2D）graphyne family that is constructed by sp and sp² hybrid carbon atoms and has aroused great concern in recent years.GDY owns extraordinary physical and chemical properties such as high mobility,specific surface area and conjugated system that make it has great potential applications in many fields.GDY could be a new generation of star carbon material after graphene.According to the different arrangement of carbon atoms,GDY could be mainly divided into three forms,namely,α,βandγ-GDY.Different GDY members present different properties.For example,γ-GDY is predicted to be a semiconductor with a band gap of≈0.46 eV and owns unique anisotropic properties.However,αandβ-grphdiyne are predicted to Dirac materials with metallic behavior.In 2010,Li and coworkers have successfully synthesizedγ-GDY on copper substrate.γ-GDY has been extensively studied in the fields of energy storage and transformation,electrochemical catalysis,nanodevices etc.β-GDY has a higher percentage of acetylenic linkages（67%）thanγ-GDY（50%）,meaning strongerπ-conjunction compared withγ-GDY and potential applications in the fields of devices,energy storage and nanocomposites.Therefore,developing an approach to synthesizeβ-GDY,and investigating its intrinsic properties and potential applications are highly desirable.From another point of view,mass production technology of GDY with high quality and low cost is a key point for the industrial future application.Almost all reported methods use copper foils as substrates.The high cost and low specific surface area of copper foil restrict the production of GDY.Increasing the specific surface area of substrates but decreasing the consumption of copper is a very important issue for mass production of GDY.Based on the viewpoints above,this thesis is devoted to investigate new GDY member preparation and mass production method of GDY.We first developed synthetic methods ofβ-GDY,including substrate catalyzed and template methods.Then,a novel freestanding 3Dγ-GDY powders synthetic method using naturally abundant diatomite as template was developed.This thesis mainly contains four parts:1.In-situ synthesis ofβ-GDY film using copper foil as substrateThe monomer（tetraethynylethene,TEE）forβ-GDY synthesis was synthesized after retrosynthetic analysis.About 25 nmβ-GDY thin film was successfully synthesized on copper foil,in which the copper foil acted as the roles of both substrate and catalyst source.The as-grown carbon film has a smooth surface and is continuous and uniform.Electrical measurements reveal the conductivity of 3.47×10^-6 S·m^-1.2.Morphology,substrate and thickness control synthesis ofβ-GDYFirstly,β-GDY nanowall was syhtesized through controlling the loading amount of TMEDA.Secondly,a direct synthesis ofβ-GDY on arbitrary no-copper substrate method was deveopled through further studying the reaction mechanism.Thirdly,a liquid/liquid interface synthetic method was developed,in which the thickness ofβ-GDY could be controlled through adjusting the reaction time,temperature and loading amount of copper acetate.3.Template-synthesis of ultrathinβ-GDY filmSingle or few layerβ-GDY with high quality synthesis is very important for the structure characterization,intrinsic properties study and device application.Herein we proposed an approach for synthesis of ultrathinβ-GDY-like film using graphene as a template by taking advantage of the strongπ-πinteraction betweenβ-GDY and graphene.The as-synthesized film presents smooth and continuous morphology and has good crystalline.Electrical measurement reveals that the film presented the conductivity of 1.30×10^-2 S·m^-1 by fabricating electronic devices onβ-GDY grown on dielectric h-BN template.4.Mass production of freestanding 3D porousγ-GDY and its application.We developed a novel freestanding 3D porousγ-GDY powders synthetic method using naturally abundant diatomite as template.The low-cost diatomite was used as substrate and copper particles act as catalyst resources that effective decrease the consumption of copper.Large-scale free-ding 3DGDY with high quality could be easily obtained and the unique features enable the 3DGDY to hold great opportunities in energy storage and catalysis.3DGDY could be applied as an anode material for lithium-ion battery and presents high specific capacity as well as excellent rate performance and long cycle life.3DGDY could also be applied as substrate for deposition of Rh and Pd clusters to fabricate Pd@3DGDY and Rh@3DGDY nanocomposite.Pd@3DGDY and Rh@3DGDY own moderate catalytic activity in dehydroxylation of benzhydrol and high catalytic activity in 4-nitrophenol reduction,respectively.