▎ 摘　　要

In this paper, we propose a facile, catalyst-free thermal annealing approach for synthesis of N-doping graphene (NG) using graphitic carbon nitride (g-C3N4) as the nitrogen source. Graphene with nitrogen content up to 13.9 % (atom %) and Brunauer-Emmett-Teller (BET) surface area of 419.6 m(2)/g can be achieved via thermal annealing composite of graphene oxide (GO) and g-C3N4. The transmission electron microscopy indicates that the NG synthesized by annealing GO/g-C3N4 composite is compact and stacked with large sheets. The atomic force microscopy reveals that the NG was less than three single graphene layers nanosheets with an apparent thickness of about 1.0 nm. This improved synthesis method for producing high nitrogen content and high BET surface area can be extended to prepare multi-element (such as B and N) doping graphene nanosheets.