Lotus seed pot-derived nitrogen enriched porous carbon for CO2 capture application

The rapid rise in anthropogenic carbon dioxide (CO2) concentration forces humanity for development of efficient carbon capture and storage approaches. Among many approaches, the adsorption of CO2 within the solid ad-sorbents is considered a feasible approach. In the present study, the lotus seed pot biomass was converted into a N-rich porous carbon adsorbent. The adsorbent preparation strategy is based on the pre-carbonization of lotus seed pot, melamine treatment and the subsequent KOH activation at elevated temperatures. The sorbents pre-pared here showed high surface areas up to the 2040 m2/g along with 0.88 cm3/g of pore volume after KOH etching. Up to 6.58 wt% nitrogen incorporated thanks to the melamine precursor. The optimized sample (LPM-650-2) presents 4.02 and 6.20 mmol/g CO2 uptake at 25 and 0 degrees C at 1 bar, respectively. We postulated that high N content and narrow pore size are the dominant factors for the high CO2 sorption capacity. Moreover, these lotus seed pot-derived carbons display great uptake reversibility, optimal heat of adsorption, rapid carbon uptake kinetics and high CO2/N2 selectivity. This study depicts a general approach to produce N-doped porous adsor-bents from the lotus seed pot and offers potential for various environmental applications including CO2 capture.