Presentation Information
[23a-32A-3]Direct growth of graphene nanostructures on stainless steel by plasma CVD
〇(D)Siyu Jia1, Jun Kameoka1, Fumihiko Maeda2, Kenji Ueda1 (1.Waseda Univ., 2.FIT)
Keywords:
Graphene nanostructures,Stainless steel substrate,PECVD
Recently, graphene/stainless steel (SUS) structures have garnered significant attention for enhancing the performance of SUS in various applications. However, high solubility and chemical reactivity of carbon in SUS introduce challenges to the synthesis of graphene structures on SUS substrate. Here, we report the synthesis of graphene with various controllable structures on SUS employing plasma enhanced chemical vapor deposition (PECVD) at lower growth temperature (500-1000 ℃) with a CH4/H2 gas ratio of 20-100%. Layer number and orientation of graphene layers can be controlled by tuning PECVD growth parameters, including the growth temperature and CH4/H2 ratio, carefully, and mono to bilayer graphene or carbon nanowalls from petal-like to branched structures were selectively formed on SUS. High-quality mono to bilayer graphene with an I2D/IG ratio of 1.1~1.3 and a smaller ID/IG ratio of 0.4 was synthesized at a lower temperature of ~600-700 ℃. Carbon nanowalls appeared above 900 ℃, and the elevated growth temperature was conducive to the compact structure with a high edge density. Notably, layer numbers of CNW formed at 100% CH4 were bilayer with an I2D/IG ratio of 0.9, owning a substantial specific surface area. Also, the growth mechanism and structure transition were found to be explained by considering the equilibrium among the amount of carbon deposited on the surface, carbon consumption through diffusion, and the precipitation of Fe3C. We believe that these results pave the way for enhancing the functionalization of SUS surface and fabricating controlled graphene/SUS structures for various applications, such as in electrochemical systems.