Graphene has become a valuable and useful nano-material due to its exceptionally high tensile strength, electrical conductivity, transparency, and being the thinnest two-dimensional material in the world. The global market for graphene was $9 million in 2012, with most of the demand from research and development in semiconductor, electronics, electric batteries, and composites.Graphene conducts heat and electricity very efficiently along its plane. The material strongly absorbs light of all visible wave-lengths, which accounts for the black color of graphite; yet a single graphene sheet is...