Large-scale in-situ synthesis of nitrogen-doped graphene using magnetically rotating arc plasma

Abstract

Free-standing nitrogen-doped graphene was synthesized using a magnetically rotating arc plasma process at atmospheric pressure in a single-step and controllable process that used CH4/C2H4/C2H2 as the carbon precursor and N2 as both the plasma gas and nitrogen precursor. Nitrogen-doped graphene with doping levels of 1.63–14.05% was produced, and nitrogen was incorporated into the graphitic structure mainly through pyrrole-type bonds. Adjusting the injection position, reaction temperature, and H/C ratio of the carbon precursor led to selectivity in terms of the doping level, nitrogen configuration, and product morphology. The relationship between the experimental conditions, intermediate complexes, and products was established, and the formation pathway of nitrogen-doped graphene was briefly discussed. This method is suitable for the mass production of nitrogen-doped graphene since it is a continuous process with a relatively high yield (>4 g/h).