From waste PET to high-performance nanofiber-assembled adsorbent aerogels and their CO2 capture performance

This study addresses plastic pollution and climate change by converting waste polyethylene terephthalate (PET) bottles into carbon dioxide (CO 2 ) capture aerogels. Using recycled polyethylene terephthalate (rPET) and chitosan (CS) as raw materials, we prepared a hierarchical porous aerogel through sequential swelling, cross-linking, and freezing of porous nanofibers. The resulting aerogel contains macropores (>50 nm), mesopores (2–50 nm), and micropores (<2 nm). Its CO 2 adsorption abilities was achieved synergistic physical-chemical method after modification with triethylenetetramine (TETA). The designed hierarchical pore structure was meticulously governed by humidity, cross-linking. The optimized aerogel (rPET/CS-2-B) with 9.51 mmol/g amines achieved a high CO 2 uptake of 3.11 mmol/g at 273 K. Under simulated flue gas (15 % CO 2 / 85 % N 2 ), the best-performing sample achieved CO 2 adsorption capacities as high as 2.99 mmol/g under dry conditions and 4.10 mmol/g under humid conditions. This work offers a novel strategy for waste upcycling and designing hierarchical porous materials for carbon capture.