Synthesis of three-dimensional nitrogen-doped graphene/polyaniline hydrogels for high performance supercapacitor applications

Three-dimensional nitrogen-doped graphene/polyaniline hydrogels (RGNP) was synthesized by facile hydrothermal method with graphene oxide (GO) and polyaniline nanorods (PANI-NRs), and urea as the reducing agent and nitrogen source. The structures and morphologies of the composites were characterized by various techniques, and electrochemical properties were also investigated. X-ray photoelectron spectroscopy (XPS) demonstrated nitrogen atom was doped into graphene and scanning electron microscopy (SEM) indicated PANI-NRs fully inset into the three-dimensional graphene layers. The RGNP composite electrode exhibited the significantly improved electrochemical performances compared to the undoped equivalents or the separate components. The specific capacitance is up to 589.3 Fg(-1) at current density of 3 mA cm(-2) in 1 M H2SO4 electrolyte, which also displays superior pseudocapacitive cycling stability (retention of 80.5% after 500 cycles). In addition, good capacitance retention rate (80.2% at 30 mA cm(-2)) has been achieved. These results indicate that the RGNP composite electrode can be applied for high performance supercapacitor.