Nitrogen-Doped Porous Carbons Derived from Polypyrrole-Based Aerogels for Gas Uptake and Supercapacitors

A novel polypyrrole-based aerogel (PPA) with a three-dimensional structure is synthesized through a simple hydrothermal process of homogeneous dispersion consisting of pyrrole and a block copolymer, followed by freeze-drying. The block copolymer plays the role of dispersant, which can be ascribed to the hydrophilic–hydrophobic interaction between pyrrole-based units and the block copolymer. Compared with a conventional bulk polypyrrole powder, the PPA exhibits higher porous attributes, which provide favorable conditions to the subsequent activation procedure. A nitrogen-doped porous carbon (NPC) with high porosity is then prepared after a physical activation treatment of PPA using carbon dioxide as an activation agent. The structure and porous property of the NPC are characterized by scanning electron microscopy, transmission electron microscopy, infrared spectroscopy, X-ray photoelectron spectroscopy, and nitrogen adsorption–desorption experiments. The as-made NPC-950-100 possesses a large Brunauer–Emmett–Teller specific surface area (2330 m 2 g –1 ), large pore volume (2.54 cm 3 g –1 ), and nitrogen doping (4.1 wt %). These properties result in a high carbon dioxide uptake capacity of 20.5 wt % at 273 K and 1.0 bar. Furthermore, NPC-950-60 also displays a decent specific capacitance (156 F g –1 at 0.1 A g –1 ) and an excellent long-term cycling stability (∼100% capacitance retention at 5 A g –1 after 10000 cycles).