Research On Preparation And Properties Of Graphene

Graphene, a two-dimensional nanomaterial combining one atomic layer, has high specific surface area and excellent mechanical, electrical, thermal and optical properties. Since its first isolation in 2004, researchers have suggested a large number of applications for this material in the future of technological revolutions. Graphene is considered as a potential candidate for replacing silicon in future electronic devices.This thesis introduces the structure of graphene, as well as its physical properties, potential applications and researches about preparation. In the experiment, we use the method of redox to get graphene. By intercalation and oxidation, we obtain graphite oxide from the natural flake graphite, the graphene oxide is obtained after ultrasonic dispersion. By dispersing graphene oxide in hydrazine and ammonia, we can get graphene suspension.In the process of oxidation, stirring in low speed will help oxidants and intercalatants a deep response, avoiding the oxides too dry. The suitable oxidation time is 48h. In the process of oxidation it is not appropriate to add the ultrasonic, for it will damage the size of the particles. At the end of oxidation, the layers of natural flake graphite are in a loose state, ultrasonic is usefull for the separation of the individual layers. In this method, we can get graphene oxide with great transmittance. D-band and G-band have been strengthened after oxidation. The width of the peak has been wider.The band shift in the 1580 cm-1. Weightlessness of graphene oxide occurs in 180℃.After reduction, graphene layers are thin, easily to fold. The original lattice structure has been changed. As the increase of reduction time, the G band gradually shift to longer wavelength, while the characteristic band of the D band become sharp. Weightlessness of graphene occurs in 860℃.The D-band and G-band both appear in graphene oxide and graphene. The width are wider than that of natural flake graphite. The raman intensity ratio of D/G in graphene oxide is much larger than that of natural flake graphite, also after reduction, the intensity ratio of D/G further improved.