Study On Preparation Of Graphene By Solid Carbon Source And Photoelectric Properties

Graphene is composed of a single layer of sp²-bonded carbon atoms arranged in a tow-dimensional honeycomb crystal lattice either freely suspended form or adhered on any substrate.There are many excellent physical properties,including high electrical conductivity?230,000 cm²/Vs?,high surface area(2630 m²g^-1)and almost completely transparent?97.7%?.The graphene will facilitate chemical doping,energy storage,electrochemistry,and could be utilized in supercapacitors,ultraportable screen,sensors,batteries,and so on.Recently,the study of graphene is not limited to the thin layers of graphene and large size single crystals of graphene.The study of graphene fibers is increasing.The main research work and conclusions are summarized as follows:?1?In a short time?3mins?,we present an successful method to synthetise large-area monolayer graphene?97.5%coverage?by atmospheric pressure chemical vapor deposition?APCVD?on Cu foils using polystyrene?PS?.Raman spectroscopy,transmission electron microscopy?TEM?and scanning electron microscopy?SEM?confirm the graphene film thickness and uniformity.The graphene films show high optical transmittance?97.42%?and electrical conductivity?1.2×10³?/??on the glass substrates.The magnetic transport studies indicate that the monolayer graphene has high carrier mobility(3395 cm²V^-1S^-1,25 K).?2?In an appropriate time?480min?,we present an efficient method to synthetise millimeter-size single-crystal monolayer graphene by atmospheric pressure chemical vapor deposition?APCVD?on Cu foils using polystyrene?PS?.The Raman spectroscopy,transmission electron microscopy?TEM?,and scanning electron microscopy?SEM?confirm the graphene film thickness,uniformity,structure and morphology.?3?we successfully prepared a macroscopic graphene fiber by self-assembling chemical vapor deposition?CVD?-grown graphene nanofibers in organic solvent.The well-dispersed PAN nanofibers were sprayed onto the copper surface in an electrified thin liquid jet by electrospinning.The successive CVD growth process induces the formation of graphene nanofibers using a PAN-solid source of carbon and a copper catalyst.From the self-assembly process in the organic solvent,we achieved a crumpled and macroscopic graphene fiber structure.The typical electrical conductivity of graphene fibers reaches up to 4.59×10³ S/m.The cyclic voltammetry shows typical capacitive behavior for the graphene fibers-supercapacitor with the capacitance values 158 mF/cm³at scale rate 10mA/s.The change in the cyclic voltammetry characteristics was negligible at 180°bending,with excellent cycling performance.These results demonstrated that the macroscopic graphene fibers effectively functioned fabrics in real-world applications.