(70d) In Situ One-Step Synthesis of Hierarchical Nitrogen-Doped Porous Carbons Derived from Metal-Organic Frameworks for Supercapacitors

Undoped porous carbon is a widely explored electrode material for supercapacitors due to its low cost, good stability, and high surface area. However, undoped porous carbon shows limited performance since it stores charge by a single mechanism via the electric double layer. Recently, nitrogen-doped porous carbon was found to exhibit enhanced electrochemical performance due to its altered chemical structure and additional pseudocapacitance originating from nitrogen heteroatoms. To synthesize nitrogen-doped porous carbons various preparation methods have been explored such as chemical vapor deposition, plasma treatment, thermal annealing, etc. Most of these methods require multiple steps and are not easily scaled. Furthermore, it is very challenging to control nitrogen content.

           Here, we report the synthesis of nitrogen-doped porous carbon by one-step carbonization of isorecticular metal-organic frameworks (IRMOF-3). No additional template or pore-forming agent, or carbon and nitrogen sources are required. IRMOF-3 plays the role of both carbon and nitrogen sources as well as a self-template. Furthermore, the nitrogen content can be fine-tuned by changing carbonization temperature. The synthesized nitrogen-doped porous carbon exhibits excellent capacitance as high as 239 F g^-1, which is much higher than analogous nitrogen-free porous carbons.