ABSTRACT
Graphene, the first 2-D layered material, has gained attention due to its high electrical/thermal conductivities, high chemical/electrochemical stability, high flexibility /elasticity and ~97.7% transparency to white light, bestowed by delocalized π cloud over carbon sheets. Despite excellent characteristics, high-quality graphene finds itself wanting for many applications. Hence, to fully exploit the potential of graphene, its derivatives such as graphene oxide and reduced graphene oxide, along with their nanocomposites with metal oxides such as ZnO, TiO2 and SnO2, are being explored. Theyhave shown remarkable applications in electrochemical energy storage and conversion, sensing, catalysis and transistors. Graphene derivatives have both aromatic and aliphatic domains which expand the surface interactions, hence paving way for functionalization with polymers, nanostructures and other carbon allotropes. For instance, functionalization of graphene enhances the active sites, which in turn hones the catalytic activity. On the other hand, it’s astonishing that graphene is inert to poisoning effects for catalysis in fuel cells on being used alongside platinum. This chapter gives a brief account about the modern progresses in graphene derivative and its nanocomposites. Their utility in energy application such as electrodes in fuel cells, solar cells, lithium batteries, supercapacitors and gas sensors with reduced size and increased sensitivity, flexible optoelectronic devices as display and touch screen in electronic gadgets have been discussed.
