Molecular dynamics simulation study of graphene synthesis by rotating arc plasma.

ABSTRACT

The rotating arc plasma method, based on its unique characteristics, provides a simple, efficient, and catalyst-free approach for graphene material synthesis. This study employs molecular dynamics simulations to theoretically investigate the detailed growth process of graphene at the atomic scale using plasma. During the growth process, different radicals serve as dissociation precursors within the plasma. Simulation results indicate that the growth process of graphene clusters involves three stages extension of carbon clusters, cyclization of carbon chains, and coalescence of clusters into sheets. Firstly, the precursor concentration affects the size of graphene clusters; increasing the precursor concentration enlarges the cluster size but also increases the likelihood of curling. Secondly, increasing the hydrogen content in the precursor can reduce the growth rate of clusters, decrease dangling bonds at the periphery of clusters, thereby slowing down cluster closure and maintaining a well-defined sheet structure. Lastly, appropriately elevating the simulation temperature can enhance the reaction rate during the simulation process without altering the reaction pathway. These research findings establish the foundation for understanding the growth mechanism of graphene.