Solid State Synthesis Of Graphene And Investigation Its Magnetic And Electrochemical Propetries

Carbon materials belong to common materials on Earth, but it is also the most special one. Carbon could not only form superhard diamond but also soft graphite. For the past twenty years, carbon materials have always been the frontiers of scientific and technological innovations. The discovery of C60in1985and carbon nanotubes in1991cause huge research interests on this area. In2004, Geim with his group members in Manchester University found graphene, while mechanical stripping graphite, which is confirmed to be a single layer or a thin layer of new two-dimensional atomic crystal. The discovery of graphene enriches the family of carbon materials formed from zero-dimensional fullerenes, one-dimensional carbon nanotubes, two-dimensional graphene to three-dimensional diamond and graphite integrally. Graphene exhibits excellent physical and chemical properties, such as strength of graphene have been tested up to130GPa, which is more than100times that of steel; its carrier mobility rate of1.5×104cm·V-1·s-1, is two times of indium antimonide, currently known for having the highest migration rate; graphene has thermal conductivity up to5×103W·m-1·K-1, which is3times that of diamond.The focuses of the current studies are on the preparation, electrochemical, optical and magnetic properties of graphene. However, previous methods focused on the preparation of this material in liquid phase, which not only cause a lot of pollution but also need several complicated reactions. Developing novel synthetic method will greatly promote the development of carbon materials. Based on the above considerations, graphene can be synthesized via novel solid-state methods. And the Raman spectrum of materials was also investigated. The characteristic peaks of Raman were determined. Through the high temperature and high pressure test, graphene can be hydrogenated. And its magnetic properties were also characterized, which proved that the hydrogenation can lead to ferromagnetism.Through high-temperature solid-state synthesis, graphene sheet doped vanadium nitride composites can be obtained. Experimental characterization of TEM, cyclic voltammetry and charge-discharge curve of composite before and after doping shows that carbon nano sheet doping can improve the composites’supercapacitor performance. The experimental results also opened up new avenues for the doping of nitride.