Hierarchical porous N-doped carbon xerogels for high performance CO2 capture and supercapacitor

Novel microporous carbon xerogels (CX-HMTAs) with different morphologies and well-developed porosity were successfully fabricated. The hierarchical pore, surface structure, and nitrogen content could be easily controlled by adjusting the amount of hexamethylenetetramine (HMTA). The samples as-obtained exhibited high micropore volume and large specific surface area, which were applied as supercapacitor electrodes and CO2 capture materials. The CX-HMTA4 with a moderate concentration of HMTA (0.72 %) afforded the highest CO2 adsorption capability with 4.21 mmol g-1 at 273 K and 1 bar, and excellent ideal adsorption solution theory (IAST) selectivity with 70 for CO2/N2 capture at 298 K. Moreover, the CX-HMTA4 were simultaneously conducted as a supercapacitor electrode, and gave a maximum specific capacitance of 161 F g-1 and high stability (retained 99.4 % capacity after 1000 cycles) in 6 M KOH electrolyte at 1 A g-1, showed a great advance when compared with most reported benchmark carbon materials. The multifunctional porous carbon materials presented herein were facilely prepared without any activation, exhibiting considerable potentials for large-scale gas adsorption/separation and electrochemical energy storage.