One-step synthesis of K3PO4-activated phosphorus-enriched carbons for enhanced carbon capture

To date, most studies on porous carbon have focused on enhancing COQ uptake capacity by decorating the carbon surface with nitrogen (N) or sulfur (S) functional groups. However, a literature survey reveals a notable gap in research on phosphorus (P)-doped porous carbon for surface modification. To address this gap, the present study focuses on the synthesis of P-decorated carbons using lotus petiole biomass as a renewable and sustainable precursor. This was achieved through a single-step process involving P-doping and chemical activation with tripotassium phosphate (K3PO4) of carbonized lotus petiole at elevated temperatures. The resulting P-doped porous carbons exhibited advanced textural properties, with a maximum surface area of 472 m2/g, a total pore volume of 0.27 cm3 /g, and phosphorus doping of up to 4.63 wt%. The optimal carbon-based adsorbent demonstrated COQ adsorption capacities of 2.57 mmol/g at 25 degrees C and 3.36 mmol/g at 0 degrees C under 1 bar pressure. Additionally, the materials showed excellent durability, exhibiting almost no change in performance after consecutive adsorption-desorption cycles. These P-doped porous carbons also displayed high COQ/NQselectivity, moderate heat of adsorption, rapid adsorption kinetics, and outstanding dynamic COQ capture performance under continuous gas flow conditions. This study provides a novel and sustainable approach to converting lotus petioles into high-performance adsorbents, with significant implications for achieving carbon neutrality and advancing environmental sustainability.