Nitrogen-doped graphene hollow nanospheres as novel electrode materials for s…

Abstract. Nitrogen-doped graphene hollow spheres (NGHS) have been prepared by a simple layer-by-layer assembly of graphene oxide (GO) and polyaniline (PANI) on polystyrene (PS) nanospheres, followed by calcination to remove the PS template and realize the carbonization of PANI. The resultant NGHS has a high nitrogen content of 8.7 atom%, in which various nitrogen species, such as pyridinic-…