Reduction And Self-assembly Of Graphene Oxide For Preparing Functional Graphene Materials And Its Performance Study

Graphene, as a novel carbon material which is characterized by uniquetwo-dimensional structure and fascinating physical and chemical properties, shows itsgreat potential in many fields, such as energy storage and conversion, environment，catalyst and so on. With a purpose to promote the basic research and application ofgraphene, this thesis focuses on:GO was successfully reduced and modified by-ray irradiation in an EDA/watersolution under the protection of nitrogen. The chemical structural changes due to theradiation-induced reduction are proved by means of UV-Vis, FT-IR, XRD and TGanalysis. Apart from the elimination of the hydroxyl and epoxide groups, adecarboxylation effect is demonstrated, but some EDA molecules are attached onto theRMGO sheet due to the recombination of radicals.We have demonstrated that the GO sheets could be reduced and functionalizedefficiently by EDA in an aqueous system under moderate conditions for preparation theFL-RGO. Such a few-layer structured macroassembly shows good conductivity andexcellent electrochemical performance for use in energy storage and other applications.The mechanism for chemical functionalization of GO has been proposed and will behelpful for exploitation of the novel strategies for three-dimensional (3D) RGOframework preparation. This result of XPS spectroscopy study illustrates that thereaction might reach the equilibrium state within8h revealing the EDA has strongreduction capability to GO. And the as-prepared FL-RGO shows good electrochemicalstability performance in lithium ion batteries.We successfully prepared compressive graphene aerogels by reacting GO withEDA via chemical-reduction assembly at80oC for24hours and then freeze-drying. Theaerogels, with density ranges from4.4to7.9mg/cm3, hold good compressibility in bothair and organic liquids. The electrical resistance of the aerogel is variable undercompress and proportional to the strain. Also the excellent fire-resistance allows the aerogel re-usable after burnt. The high porosity was estimated to be99.6%, with asuperhydrophobicity with a contact angle of155oinside, thus allowing the aerogels toabsorb different organic liquids, with the capacity varying from100to250dependingon the density of the organic liquids. Due to the hydrophobicity of the aerogel, it canfloat on the water for absorbing the oil and then play as a porous carbon wick tocombustion continually and recurrently. Finally, the absorbed oil can be removed bycombustion, while the absorption-distillation and the absorption-squeezing process weresuccessfully demonstrated for the oil collection. Especially the absorption-squeezingprocess is quick and less energy consumption which is more attractive in applications,where the aerogel acts as an organogel during the process.We demonstrate a facile approach for fabrication of macroscopic GFs with arelatively low concentrated GO solution (1-4mg/mL) as the precursor and lowtemperature chemical reduction-assembly as the method. Flexible graphene fibers (GFs)with an ultimate elongation of20%and a tensile strength up to150MPa were prepared.The bend-conductivity tests and laundering-conductivity durability tests demonstratethe flexibility and resistance to bend and laundering of our GFs. Large scale preparationof graphene fibers can be done by scaling up the pipelines.