Azure B microspheres/nitrogen-doped reduced graphene oxide: Non-covalent interactions based crosslinking fabrication for high-performance supercapacitors

Abstract

Organic molecules with conjugated π-bonds are promising electrode materials for supercapacitors due to their outstanding redox reversibility and structural stability. Yet they are limited for applications in supercapacitors on account of poor conductivity and inferior cyclability. In this work, a series of azure B/nitrogen-doped reduced graphene oxide (AB/N-rGO) composites are prepared via hydrothermal process and following freeze-drying. As expected, non-covalent bonds between N-rGO and AB allow them to link together and form three-dimensional porous structure, exhibiting enhanced specific capacitance and cycle life. The supercapacitive properties of AB/N-rGO composites are optimized by controlling mass ratio of graphene oxide and AB raw materials. The prepared AB/N-rGO-5 electrode exhibits optimal specific capacitance of 371 F g − 1 at 1 A g − 1 and excellent cyclic stability (94% capacitance retention after 10,000 cycles) in 1.0 M H2SO4 electrolyte. Besides, the as-assembled asymmetric supercapacitor constructed with AB/N-rGO-5 cathode and WO3 anode not only displays wide voltage window (1.55 V) and high energy density of 25.0 Wh kg−1 at power density of 387.9 W kg−1, but also exhibits prominent cyclic stability (81% capacity retention after 10,000 cycles). This work offers ideas for applications of more electroactive molecules with excellent capacitive properties in supercapacitors.