ContextThe　rotating　arc　plasma　technique　for　the　synthesis　of　nitrogen-doped　graphene　capitalizes　on　the　distinctive　attributes　of　plasma,　presenting　a　straightforward,　efficient,　and　catalyst-free　strategy　for　the　production　of　nitrogen-doped　graphene.　However,　experimental　outcomes　generally　fail　to　elucidate　the　atomic-level　mechanism　behind　this　process.　Our　research　utilizes　molecular　dynamics　simulations　to　explore　theoretically　the　formation　of　radicals　during　the　plasma-driven　reaction　between　methane　(CH4)　and　nitrogen　(N-2).　The　simulations　present　a　complex　reaction　system　comprising　nine　principal　species:　CH4,　CH3,　CN,　CH2,　HCN,　CH,　N-2,　H-2　and　H.　Notably,　HCN　and　CN　emerge　as　pivotal　precursors　for　nitrogen　doping.　Optimal　nitrogen　concentrations　enhance　the　synthesis　of　these　precursors,　whereas　excessive　nitrogen　suppresses　the　formation　of　C-2　species,　impacting　the　yield　of　nitrogen-doped　graphene.　Conversely,　higher　methane　concentrations　stimulate　the　generation　of　carbon　radicals,　augmenting　the　production　of　HCN　and　CN　and　thus,　influencing　the　properties　of　the　synthesized　material.　This　work　is　expected　to　lay　a　theoretical　foundation　for　the　refinement　of　nitrogen-doped　graphene　synthesis　processes.MethodsIn　this　investigation,　we　employed　the　LAMMPS　software　package　to　explore　the　formation　of　free　radicals　during　the　methane-nitrogen　reaction　via　molecular　dynamics　(MD)　simulations.　These　simulations　were　conducted　under　an　NVT　ensemble,　maintaining　a　constant　temperature　of　3500　K　with　a　time　step　of　0.1　fs　over　a　duration　of　1000　ps.　To　reduce　the　variability　and　enhance　the　reliability　of　the　simulation　outcomes,　each　simulation　was　meticulously　conducted　three　times　under　identical　parameters　for　subsequent　statistical　analysis.