ECR plasma-assisted single-step synthesis of hydrogenated graphene

A novel approach for synthesizing hydrogenated graphene (graphane) using an in-house developed electron cyclotron resonance (ECR) plasma enhanced chemical vapor deposition (PE-CVD) setup is reported in this article. A special type 2.45 GHz permanent magnet type ECR PE-CVD system has been created for the development of hydrogenated graphene at much lower operating temperature of 773 K in comparison to conventional thermal CVD. ECR plasma provides a significant portion of the heat. Moreover, the catalytic substrate is polycrystalline copper foil, which is first etched in resonant hydrogen plasma and annealed in presence of argon before being exposed to the gaseous plasma of the precursor inside the ECR PE-CVD reactor. Methane is employed as carbon precursor in order to maintain the ideal thermodynamic conditions for the production of hydrogenated graphene. The synthesis process in one-step is performed upon controlling the growth temperature, total pressure and synthesis time. The hydrogen exposure during ‘graphane’ development has been estimated using the in-situ quadrature residual gas analyzer (QRGA). Raman spectroscopy is performed to analyze the exposed copper foil in order to assess the quality of the synthesized material.