Graphene is an atomic-scale honeycomb lattice made of carbon atoms. It is the world's first 2D material and is one million times smaller than the diameter of a single human hair. However, it is many times stronger than steel, yet incredibly lightweight and flexible. It is electrically and thermally conductive but also transparent. As a single layer graphite, graphene has raised great interest due to its potential applications in different fields of material science for developing nanocomposites, sensors, supercapacitors, hydrogen storage, photonics and optoelectronic devices.