Molecular simulation of graphene growth by chemical deposition on nickel using polycyclic aromatic hydrocarbons

The chemical vapor deposition (CVD) synthesis using the solid/liquid carbon sources provides important alternative to economical and large-scale production of graphene-like materials. Herein, we applied the reactive molecular dynamics simulation to study the formation and growth of graphene on nickel surfaces using naphthalene/fluorene as carbon sources. The kinetic CVD process has been demonstrated. A series of fundamental mechanism steps were revealed and identified, where surface-assisted dehydrogenation reaction occurs at first stage, followed by coalescence reaction of active molecular species, which includes complicated multi-step processes. This unique behavior is different from the nucleation and growth mechanisms in the conventional graphene CVD process. The effect of annealing temperature, precursor concentration, and surface types was systematically investigated. Our result suggests that there exist optimal temperature and concentration in the CVD process. The moderate surface interaction on Ni (1 1 1) promotes the formation and growth of large and continuous graphene-like carbon network structure. Finally, we evaluate the self-healing function of surface graphene structures by extending the annealing time. Our simulation provides a new insight into the graphene surface growth and will be valuable to further develop the CVD process.