Bioinspired silkworm cocoon-like cellulose aerogels with dual functions of high-efficiency CO2 adsorption and photothermal-triggered desorption

Abstract The development of efficient and sustainable carbon dioxide (CO 2 ) capture and regeneration technologies is critical to achieving carbon neutrality. Solid-state amine-based materials still face challenges such as high regeneration energy and low efficiency. To address these challenges, we designed and fabricated a biomimetic cocoon-inspired ternary composite aerogel, employing bacterial cellulose (BC) as the supporting scaffold, polyethyleneimine (PEI) as the active adsorption component, and carbon nanotubes (CNTs) as the photothermal conversion agent. The aerogel was prepared via directional freezing followed by freeze-drying to form an ordered layered porous structure. Experimental results demonstrate that at a CNT loading of 200 wt.%, the aerogel exhibits excellent performance, achieving a CO 2 adsorption capacity of 0.076 g/g and a photothermally driven CO 2 desorption capacity of 0.050 g/g, while retaining 91.65% of its initial adsorption capacity after five adsorption–desorption cycles. Density functional theory (DFT) calculations reveal that the introduction of CNTs significantly reduces the CO 2 adsorption energy on PEI (from -20.014 kJ/mol to -34.501 kJ/mol), suggesting that the CNT/PEI composite exhibits a stronger adsorption capability toward CO 2 . Outdoor measurements further validate the CO 2 desorption capability of the BPC aerogel under natural sunlight, reaching a concentration of 1848 ppm on sunny days, markedly higher than that under cloudy conditions (938 ppm). The BC/PEI/CNT aerogel developed in this study exhibits outstanding potential in efficient CO 2 capture, photothermal-responsive regeneration, and environmental adaptability, offering a new solution for low-energy and sustainable carbon management technologies.