Effect of carrier gas on nitrogen-doped graphene in AC rotating arc plasma

Nitrogen doping is an effective way to improve the electrical and catalytic properties of graphene. Here, we used a non-thermal plasma technique with AC rotating arc to prepare nitrogen-doped graphene. This method does not need catalyst and can produce nitrogen-doped graphene in the atmospheric environment by large scale. CH 4 as the carbon source and N 2 as the nitrogen source, nitrogen-doped graphene was obtained by plasma direct synthesis. The nitrogen content in the product was analyzed by X-ray photoelectron spectroscopy and the doping level was about 1.19 at.%. It was found that H 2 and CO 2 as carrier gases can change the nitrogen doping type and content. When there was only N 2 , pyrrolic N and graphitic N were the main forms in the graphene. The addition of H 2 improved the selectivity of pyridinic N and pyrrolic N, but decreased the nitrogen doping content. CO 2 significantly increased the selectivity of pyrrolic N and increased the nitrogen doping content. In addition, the formation mechanism of nitrogen-doped graphene was briefly described in this paper. The key in this plasma production technology is to understand the effect of carrier gas on nitrogen doping, which is also instructive for mass production in industry.