Mild synthesis of holey N-doped reduced graphene oxide and its double-edged effects in polyaniline hybrids for supercapacitor application

Holey nitrogen-doped reduced graphene oxide (H-NrGO) was synthesized via a mild procedure, by refluxing graphene oxide (GO) with NH3 center dot H2O as doping reagent and H2O2 as etching reagent, followed by chemical reduction. The holey nitrogen-doped reduced graphene oxide/polyaniline (H-NrGO/PANI) hybrids were then prepared by the chemical oxidation polymerization of aniline in the presence of the holey nitrogen-doped graphene oxide (H-NGO) and reduction with hydrazine. The electrochemical performance of the H-NrGO/PANI hybrids was investigated in comparison with the reduced graphene oxide/polyaniline (rGO/PANI) hybrid prepared under the same condition with GO. The optimized one, H-NrGO/PANI-10 electrode, possessed higher specific capacitance of 746 F g(-1) and retention of 97% after 2000 CV cycles, than the rGO/PANI-10 electrode of 618 F g(-1) and 96%, respectively. Based on the electrochemical performance, the double-edged effects of the H-NrGO were proposed for its PANI-based hybrids in aqueous electrolyte: enhancing the specific capacitance but declining the cycling life, due to its hydrophilic holey and N-doped structure. Even though, the symmetric supercapacitors (SCs) fabricated with the H-NrGO/PANI-10 electrodes possessed a higher specific capacitance of 510 F g(-1) at 1.0 A g(-1) and a higher specific capacitance retention of 74% after 2000 cycles at 3.0 A g(-1) than the rGO/PANI-10 SC. (C) 2019 Elsevier Ltd. All rights reserved.