“…The bottom-up approach consists of standard techniques such as epitaxial growth using metallic substrates by means of CVD [10, 50-54, 72, 73] or organic synthesis [23,72,74,75], which depend on the choice of precursor chemicals and thermal degradation and decomposition of the SiC [19,51,53,54,73,76]. Several other processes, such as arc discharge [29,30,77], chemical conversion [23,27,77,78], CO reduction [79], CNT unzipping [35,38,[80][81][82], and self-organization of surfactants [83][84][85] have also been tried for synthesis of graphene and its derivatives. Of all these processes, CVD and epitaxial growth, which produce bantam quantities of flawless graphene sheets with larger size [49], may in future be attractive for mass-scale graphene production, in contrast to mechanical cleaving.…”