Nitrogen-doped graphene has been demonstrated to be an excellent multifunctional material due to its intriguing features such as outstanding electrocatalytic activity, high electrical conductivity, and good chemical stability as well as wettability. However, synthesizing the nitrogen-doped graphene with a high nitrogen content and large specific surface area is still a challenge. In this study, we prepared a nitrogen-doped graphene aerogel (NGA) with high porosity by means of a simple hydrothermal reaction, in which graphene oxide and ammonia are adopted as carbon and nitrogen source, respectively. The microstructure, morphology, porous properties, and chemical composition of NGA were well-disclosed by a variety of characterization methods, such as scanning electron microscopy, nitrogen adsorption-desorption measurements, X-ray photoelectron spectroscopy, and Raman spectroscopy. The as-made NGA displays a large Brunauer-Emmett-Teller specific surface area (830 m2 g-1), high nitrogen content (8.4 atom %), and excellent electrical conductivity and wettability. On the basis of these features, the as-made NGA shows superior capacitive behavior (223 F g-1 at 0.2 A g-1) and long-term cycling performance in 1.0 mol L-1 H2SO4 electrolyte. Furthermore, the NGA also possesses a high carbon dioxide uptake capacity at 1.0 bar and 273 K (11.3 wt %).Keywords: graphene; supercapacitor; porous material; aerogel; adsorbent