Graphene Hydrogel Decorated with N, O Co-Doped Carbon Dots for Flexible Supercapacitor Electrodes

Abstract

Waste fiberboards were used to produce N, O co-doped carbon dots (CDs) by acid etching method. The graphene hydrogels decorated with N, O co-doped CDs (GCD) were synthesized via hydrothermal method and optimized through different mass ratios. The optimal composite electrode exhibited a high specific capacitance of 335.1 F g−1 at 1 A g−1, and a good mechanical flexibility with about 90.6% capacitance retention after 500 bending/unbending cycles. Furthermore, the assembled flexible supercapacitor owned an ideal cycling stability of 83.4% after 10000 charge/discharge cycles at 5 A g−1. Such results demonstrated that N, O co-doped CDs played an essential and unique role in composite graphene hydrogel for improving the electrochemical performance of the flexible supercapacitor.