Structure and Properties of Graphene and Chemically Modified Graphene Materials

 Graphene is an allotrope of carbon that is made up of very strongly bonded carbon atoms. The structure of graphene is a hexagonal lattice. Graphene shows sp2 hybridization and an extremely thin atomic thickness of approximately 0.345Nm. This chapter deals with graphene structure, including hybridization, critical parameters of the unit cell, the formation of σ and π bonds, electronic band structure, edge orientations, and the number and stacking order of graphene layers. The remarkable characteristics of graphene occur because of the extended chain of π conjugation that results in high charge mobility, high conductivity & high Young's modulus value. Due to these attractive properties, graphene has gained much attention. Graphene, with the unique combination of bonded carbon atom structures with its myriad and complex physical properties is balanced to have a big impact on the future of material sciences, electronics, and nanotechnology. Graphene is converted to Graphene nanoparticles, Graphene oxide nanoparticles; Polymer-based graphene composite materials and Graphene nanoribbons, etc by chemical methods. Some of the application areas are batteries and ultracapacitors for energy storage and fuel cell and solar cell for energy generation and some of the possible future directions of research have been discussed.