Controllable preparation of nitrogen-doped hierarchical and honeycomb-like porous carbon/graphene based on composites of graphene oxide and polyaniline nanorod arrays for high performance supercapacitors

The nitrogen-doped hierarchical and honeycomb-like porous carbon/graphene (PGC and GPGC) have been prepared by chemical activation of the composites of polyaniline (PANI) nanorod arrays/graphene oxide (GO), and GO/PANI nanorod arrays/GO, respectively, with KOH at 700°C. The as-prepared PGC and GPGC possessed high specific surface areas of 2703 and 2837 m 2 g −1, and their N-doping levels of 4.38 at.% and 4.72 at.% (atomic ratio), respectively. When used as electrode materials for supercapacitors, PGC and GPGC exhibited high capacitance of 465.2 F g −1 and 507 F g −1, respectively, at a current density of 1 A g −1 in 1 M H 2 SO 4 aqueous electrolytes. Furthermore, they also exhibited outstanding cycling stability up to 91.5% and 96.8% after 1000 cycles at a current density of 10 A g −1, respectively. To approach practical applications, the GPGC electrodes were assembled into a symmetric supercapacitor and delivered a specific energy up to 28.3 Wh kg −1 and a high specific power of 12112 W kg −1. Additionally, in the present work, it was also found that GO introduced into PANI nanorod arrays/GO not only controlled the structure of N-doped porous carbon/graphene, but also enhanced the electrochemical performance of electrode materials.