Deep insight into the pore size distribution of N-doped porous carbon materials on electrochemical energy storage and CO2 sorption

Nitrogen-doped porous carbon materials with controllable pore sizes are selectively prepared via carbonization of banana sheets combined with KOH activation. The resulting carbon materials, featured with a well-designed pore size distribution, high specific surface area, exhibits excellent capacitive performance in aqueous electrolyte (264 F/g at 1 A/g). More importantly, the symmetric supercapacitor exhibited a maximum specific capacitance of 155 F/g and a corresponding energy density of 48.44 Wh/kg at a current density of 1 A/g in organic electrolyte. Further investigation revealed that the enhanced supercapacitance is attributed to the pore size (especially in the range of 0.9-1.2 nm) and N-doped. The prepared carbon also displays an excellent CO2 adsorption ability due to the suitable pore size distribution as high as 5.29 mmol/g and 4.16 mmol/g at 0 degrees C and 25 degrees C under 1 bar, respectively. The present investigation will provide a new avenue for the wide application of biomass-derived porous carbon in various fields.