Solid-State Synthesis of Graphene by Induction Heating

Graphene has been demonstrated as one of the most promising materials in many areas of high-tech enterprise. Here, we present a novel approach to graphene synthesis using solid-state carbon as a precursor and induction heating as an energy source. The basic physical principle has not changed, but the induction seems to be a driver for faster synthesis of graphene, opening new horizons for rapid synthesis. Copper is saturated by carbon during the heating stage, and then carbon diffuses by the conventional surface-mediated method that is enriched by a back-diffusion process during the cooling stage. The back-diffusion step promotes a rapid graphene synthesis of sheets covering the entire surface of the copper substrate. The carbon back-diffusion process occurs at higher temperatures (<800 degree celsius) and continues through temperatures as low as 400 degree celsius. Copper saturation with carbon occurs along the {111} planes, and its atom migration or precipitation occurs through the {110} and {100} planes via a back-diffusion mechanism. However, the actual synthesis of graphene occurs in the {111} plane, which is attributed to the epitaxial match with the {0001} planes in graphitic structures. The graphene sheets vary in thickness from single to multilayered, as verified by Raman and HRTEM.