High-performance CO2 adsorption with P-doped porous carbons from lotus petiole biomass

Combating climate change and global warming generally involves reducing CO2 level from the air. To achieve this, in present study, phosphorus-doped porous carbons were prepared using biomass lotus petiole as the precursor. The synthesis procedure involves first pre-carbonization of lotus petiole at elevated temperature and secondly, introducing phosphorus atoms by phytic acid modification, which then chemically activated at various temperature and amount of KOH. Resulting carbons present advanced textural feature (the BET surface area of up to 1456 m2/g along with 0.68 cm3/g of pore volume) and high amount of P doping (up to 3.39 wt%). These Pdoped adsorbent have exhibited excellent CO2 capture capacity, achieving 4.00 mmol/g at 25 degrees C and 6.05 mmol/ g at 0 degrees C at about 1 bar pressure. Additionally, these adsorbents demonstrated practical stability for maintaining over 97 % adsorption capacity after 5 sequential cycles as well as high CO2/N2 selecivity, moderate heat of adsorption, fast adsorption kinetics and good dynamic CO2 capture capacity from contineous flowing gas mixture. Thus, based on the superior CO2 capture performance of the as-prepared adsorbents, a new method of converting biomass into higly functional carbon materials is proposed for the field of carbon neutrality.