High-performance amino-crosslinked phosphorylated microcrystalline cellulose/MoS₂ hybrid aerogel for polystyrene...

Currently, the development of high-performance adsorbents for the removal of nanoplastics in complex aquatic environments is challenging. In this study, a functionalized polyethyleneimine-phosphorylated microcrystalline cellulose/MoS₂ (PEI-PMCC/MoS₂) hybrid aerogel was prepared and applied to remove carboxyl-modified polystyrene (PS-COOH) nanoplastics from the aqueous solution. Benefiting from the introduced functional groups and the expanded lamellar structure in MoS₂ nanosheets as well as the highly porous 3D structure of the aerogel, PEI-PMCC/MoS₂ demonstrated high efficiency in PS-COOH nanoplastics removal, achieving a 402.4 ± 7.5 mg/g maximum adsorption capacity at the optimal adsorption pH of 7.0 (C₀ = 300 mg/L). The adsorption isotherm and kinetics data fitted well with the Langmuir and pseudo-second-order models, respectively, suggesting that the removal of PS-COOH nanoplastics was dominated by the monolayer chemisorption process, and the thermodynamic studies revealed the exothermic nature of the spontaneous adsorption process. Furthermore, the adsorption performance of PEI-PMCC/MoS₂ in different complex aqueous environments, as well as its reusability, was evaluated, and the interactions between PEI-PMCC/MoS₂ and PS-COOH nanoplastics were analyzed to elaborate the adsorption mechanism. These results confirmed the high nanoplastics removal efficiency and favorable reusability in PEI-PMCC/MoS₂, laying a solid foundation for developing high-performance adsorbents for nanoplastics removal.