Ultra-High Specific Surface Area Porous Carbons Derived from Chinese Herbal Residues with Potential Applications in Supercapacitors and Co2 Capture

Ultra-high specific surface area (SSA, > 3000 m2 g−1) porous carbons are promising materials for energy storage and gas selective adsorption and separation. In this work, we have successfully synthesized ultra-high SSA porous carbons (up to 3410 m2 g−1) derived from Chinese herbal residues with the potential applications in high-performance supercapacitors and effective CO2 capture. The obtained ultra-high SSA porous carbons display good electrochemical performance as the electrode materials for supercapacitors with a specific capacitance of up to 291.6 F g−1 at 1 A g−1 in 6 M KOH, as well as a superior rate retention with a capacitance of 210.0 F g−1 at 50 A g−1. The energy density of the symmetric supercapacitor reaches 10.2 Wh kg−1 (24.3 kW kg−1 in 1 M Na2SO4), which is far beyond that of the commercial porous carbon YP-80F (3.0 Wh kg−1). Moreover, as the CO2 capture materials, the ultra-high SSA porous carbons display high CO2 uptake capacities (up to 4.88 mmol g−1 at 273 K, 1 bar). Our work provides an effective strategy to synthesize ultra-high SSA porous carbons derived from Chinese herbal residues which simultaneously possess the potential for energy storage and CO2 capture.