“…Graphene, a two-dimensional (2D), single-layer planar sheet of sp 2 -hybridized carbon atoms densely packed in a honeycomb crystal lattice, is considered the first true 2D-material (i.e., one atom thick) to become a keystone in material science research ever since it was isolated from lumps of graphite in 2004 by Geim and Novoselov et al [ 1 , 2 , 3 , 4 , 5 , 6 , 7 ]. This success was motivated by its unique electronic, electrochemical, optical, thermal and mechanical properties, leading to its application in a variety of research areas including electronics, sensing, energy conversion and storage, water purification and biomedical applications [ 1 , 2 , 3 , 5 , 6 , 7 , 8 ]. Graphene is the first example belonging to the large graphene family of nanomaterials, differing from each other in terms of their number of layers, size and surface properties [ 1 , 2 , 3 , 6 , 7 ].…”