Ultrahigh surface area n-doped hierarchically porous carbon for enhanced CO₂ capture and electrochemical energy storage

Facile synthesis of ultrahigh surface area porous carbons with well-defined functionalities such as N-doping remains a formidable challenge as extensive pore creation results in significant damage to the active sites. Herein, an ultrahigh surface area, N-doped hierarchically porous carbon was prepared through a multicomponent co-assembly approach. The resultant N-doped hierarchically porous carbon (N-HPC) possessed an ultrahigh surface area (≈1960 m² g⁻¹), a uniform interpenetrating micropore (≈1.3 nm) and large mesopore (≈7.6 nm) size, and high N-doping in the carbon frameworks (≈5 wt %). The N-HPC exhibited a high specific capacitance (358 F g⁻¹ at 0.5 A g⁻¹) as a supercapacitor electrode in aqueous alkaline electrolyte with a stable cycling performance after10 000 charge/discharge cycles. Moreover, as a CO₂ absorbent, N-HPC displayed an adsorption capacity of 29.0 mmol g⁻¹ at 0 °C under a high pressure of 30 bar.