Naturally nitrogen and calcium-doped nanoporous carbon from pine cone with superior CO₂ capture capacities

A highly effective nanoporous CO₂ sorbent with naturally doped nitrogen and calcium elements, derived from pine-cone biomass, shows superior CO₂ capture performance. The sorbent was produced from carbonization and KOH activation of dried pine cones, and possess a highly nanoporous structure with a specific surface area and a pore volume up to 2110 m²/g and 0.89 cm³/g, respectively. The highest CO₂ uptake of 20.9 wt % (under 1 bar CO₂ and 25°C) was achieved in a porous structure with relatively high levels of nitrogen and calcium dopants inherited from the biomass precursor. Further porosity and elemental analyses show that CO₂ sorption is enhanced by both highly developed ultramicroporous structure (<0.7 nm) and well-dispersed nitrogen and metal dopants in carbon sorbents.