Ultra-high specific surface area porous carbons derived from Chinese medicinal 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 synthesized porous carbons with ultra-high SSAs (up to 3410 m2 g−1) and large pore volumes (up to 2.095 cm3 g−1) from Chinese medicinal herbal residues (CHRs). The obtained ultra-high SSA porous carbons display good electrochemical performance as the electrode materials for supercapacitors with specific capacitances of up to 291.6 F g−1 at 1 A g−1 in 6 M KOH, as well as high rate retentions (72.0–82.1 %) at 50 A g−1. Moreover, as the CO2 capture materials, the ultra-high SSA porous carbons display high CO2 uptake capacities (up to 30.0 mmol g−1 at 298 K, 30 bar). Our work provides an effective strategy to fabricate ultra-high SSA CHRs derived porous carbons which simultaneously possess the great potential for energy storage and CO2 capture.