Research On The Transition Of Amouphous Carbon To Garaphene By Matal Catalyst

Graphene is a kind of two-dimensional materials which having a single-atom-thick, and be generated from carbon atoms’ SP2 hybridization. The properties of graphene is superior, such as ultra-high electron mobility(200000cm2v-1s-1), excellent mechanical properties(Young’s modulus 1100 GPa, breaking strength 13GPa), good light transmittance(> 97%) and large specific surface area(2630m2/g), which make graphene not only become the favor of scientists from the discovery, but get lots of research in the energy industry, information materials, bio-engineering and many other fields. Graphene is one of the brightest material in the 21 st century, its discoverers is awarded the Nobel Prize just after four years.Through the development of these 11 years, the graphene research has made great progress,but now the major bottleneck of industrial applications of graphene is still the optimization of graphene’s preparation technology, so it is an urgent need to address the problem how to make the high-quality graphene which layers are controlled.In this paper, graphene is prepared on the carbon source of the amorphous carbon and the catalytic metal of Cu and Ni, by constructing the "sandwich" structure of substrate-amorphous carbon-catalytic metal, under high-temperature annealing in vacuum. The effects of different catalytic metal, different temperatures and different parameters of the amorphous carbon content to generate graphene is studied, and then find a process route to prepare graphene controllably.The study finds that temperature is an important parameter to generate graphene. Under the case of Cu catalysis, graphene can not be prepared below the temperature of 900℃, 900℃ is an ideal temperature, if the temperature continues to rise, not only the obtained graphene’s defects but the carbon content of impurities will increase. At the same temperature, the graphene layers can be controlled by changing the holding time, its effect is far better than by reducing carbon content, which make the graphene be monolayer, but it is in small size and has the larger defects.The graphene is prepared by following steps. Firstly, by the way of co-deposition to introduce Ni, and the use of Cu-Ni ally to catalyze which makes the amorphous carbon dissolve in the mental Ni at a high temperature,then the use of Cu to restrain the amount of metal C, and in the cooling process of the metal Cu and Ni are miscible, lastly, C is precipitated on the surface.With addition of Ni, the temperature required for the preparation of graphene reduced, but need to facilitate the holding time for the amorphous carbon dissolved in the metal Ni, the graphene is single layer under the 800℃ for 5 minutes, the amount of graphene increased significantly and graphene has fewer defects. And multi-graphene can be obtained by increasing the holding time.If excessive content of Ni, the structural defects of graphene is increases,and the number of layers is difficult to control.The ideal content of Ni metal is 13.63at%.