Fabrication of nitrogen-doped porous electrically conductive carbon aerogel from waste cabbage for supercapacitors and oil/water separation

Nitrogen-doped porous carbon aerogels were prepared by using low-cost and high yield cabbages as carbon source via a mild method, including hydrothermal, freeze-drying, and carbonization processes. Owing to natural structure and nitrogen-containing features, the as-prepared carbon aerogels exhibited hierarchical 3D network porous structure with suitable nitrogen-doped and high conductivity. With such unique structural characteristics, these carbon aerogels displayed a superior performance, such as superior capacitance of 291 F g −1 with high large capacitance retention of 96.76% after 10,000 cycles in 6 M KOH electrolyte, as well as high energy density of 97.1 Wh kg −1 with and long cycling stability of 92.87% after 10,000 cycles in ionic liquid. Moreover, these superoleophilic carbon aerogels exhibited excellent adsorption capacity and recyclability for various oils and organic solvents. This work fully utilized the advantages of the cabbage leaves derived porous carbon aerogels as a promising “green” candidate to apply in low-prices and high-performance energy storage devices and adsorbent materials.