Optimized Synthesis of Nitrogen-Doped Carbon with Extremely High Surface Area for Adsorption and Supercapacitor

Abstract Carbon based materials are vital for many scientific applications because of their well-developed pore structure and functionalized surface. However, to achieve high surface area, harsh synthesis conditions, such as the use of high temperatures and corrosive activators, are usually needed, which allows the functional groups to gradually decompose or react in return, resulting in very poor surface chemistry. Herein, a novel and effective approach including the optimized carbonization and activation processes is proposed. The molten zinc salt can not only significantly enhance the stability of the nitrogen source through the strong Lewis acid-base interactions,but also strengthen the pore-forming process. By varying the activating temperature, the as-prepared waste biomass derived porous carbons exhibit an extremely high surface area (up to 4098 m2 g−1) and rich nitrogen contents (from 0.67 to 6.18 wt%). Interestingly, beyond the disordered cross-linked network microtopography, there are numerous unique microsphere and cubic structures decorated on the carbon surface. In terms their potential applications, these porous carbons simultaneously show a record-high acetone static uptake (1678 mg g−1 at 25°C and 18 kPa) and ultrahigh capacitor property (specific capacitance of 346 F/g-1 and specific energy density of 39.4 Wh/kg-1).