Graphene is an allotrope of carbon that consists of a sheet of one-atom thick sp− 2

bonded carbon atoms as shown in Figure 13.1a. Since its isolation in 2004,1 graphene has attracted significant attention due to its outstanding electrical and physical properties.2-5 Single-layer graphene sheets exhibit properties such as high transparency, high electron mobility, excellent mechanical strength, and impressive thermal conductivity. It has been proposed for applications in a variety of different fields and technologies, including solar cells,6-11 energy storage,12 batteries,13 fuel cells,14 and in biotechnology. Although many applications of graphene have been suggested, its commercial deployment remains limited due to the inherent difficulties of scalability, reproducibility, and cost-effectively preparing graphene samples of high quality.