Free-standing N-doped reduced graphene oxide papers decorated with iron oxide nanoparticles: stable supercapacitor electrodes

Abstract

In this study, graphene oxide paper is obtained via vacuum-assisted filtration of graphene oxide solution to prepare self-standing electrodes for supercapacitors. Simultaneous reduction and N-doping of graphene oxide paper are performed by chemical reduction followed by thermal annealing. Influence of different reduction techniques on the electrochemical properties of the self-standing papers is investigated. N-doped reduced graphene oxide papers are decorated with iron oxide nanoparticles to increase the energy density of the material. Increasing the amount of iron oxide nanoparticles in the composite paper results in enhanced capacitance. In the galvanostatic charge-discharge measurements, iron oxide/N-doped reduced graphene oxide electrode exhibits specific capacitance of 203 F g(-1) at 0.5 mA cm(-2). This value is remarkable since the electrode has a high mass loading of 2 mg cm(-2), which shows that the electrode can be used for practical purposes. Moreover, these electrodes operate in a wide potential window (1.6 V) and exhibit 79 % capacitance retention at 10000 cycles.