Facile synthesis of structure-controllable, N-doped graphene aerogels and their application in supercapacitors

N-doped graphene aerogels (NGAs) were first synthesized by using graphene oxide (GO) and melamine via a self-assembly process by one-pot hydrothermal method. The morphology and structure of the as-prepared materials were characterized by means of scanning electron microscopy, transmission electron microscopy, X-ray diffraction, XPS spectroscopy and nitrogen adsorption/desorption measurement. The electrochemical performances of NGAs were studied by cyclic voltammetry, galvanostatic charge/discharge and impedance spectroscopy measurements. Importantly, the microstructure, surface area and capacitance of NGAs could be facilely controlled by changing the melamine/GO mass ratio. Compared with the pure graphene aerogel (80 F g(-1) at 0.5 A g(-1)), NGA-3 with the mass ratio of 1/15 displayed enhanced specific capacitance (116 F g(-1)) and retained 94% of its initial capacitance after 1000 cycles. It provided a possible way to obtain graphene based materials with high surface area and capacitance.