Magnetic CO2-responsive aerogels with Ag/Fe MOF-derived carbon for adsorption and photo-Fenton-like degradation of organic pollutants

Eliminating various organic pollutants from wastewater continues to pose a major environmental issue. Herein, CO 2 -responsive magnetic bio-aerogels (Ag/Fe-NC@DCG) integrating “smart” adsorption and photo-Fenton-like degradation were constructed by embedding surface plasmon resonance (SPR)-enhanced MOF-derived Ag/Fe nanocarbon (Ag/Fe-NC) into cellulose nanocrystal reinforced gelatin aerogels, followed by surface functionalization with a CO₂-responsive silane coupling agent ( N, N -diethyl-3-aminopropyltrimethoxysilane). The resulting aerogels exhibited outstanding adsorption capacities toward charged pollutants, reaching 859.62 mg/g for negatively charged methyl orange (MO) and 635.92 mg/g for positively charged methylene blue (MEB), governed by electrostatic interactions and hydrogen bonding. The adsorption process was well described by the Langmuir adsorption isotherm model and pseudo-second-order adsorption kinetic model. Remarkably, CO 2 served as a trigger gas to enable rapid and selective adsorption of negatively charged organic pollutants from the mixture, thereby realizing CO 2 -regulated selective adsorption. As anticipated, under visible light irradiation in the presence of peroxymonosulfate (PMS), the Ag/Fe-NC component efficiently catalyzed photo-Fenton-like reactions, leading to significantly enhancing removal efficiencies for both charged and neutral organic pollutants. For neutral bisphenol A (BPA) and amphoteric tetracycline hydrochloride (TCH) that were initially unadsorbed, their removal efficiencies rose dramatically from 5.24% and 12.79% to 90.67% and 97.40%, respectively. Additionally, the aerogels demonstrated excellent recyclability, mechanical robustness, and antibacterial activity. Overall, this work presents a versatile and sustainable aerogel platform that integrates CO 2 -triggered selective adsorption with photo-Fenton-like degradation, offering a prospective pathway for wastewater remediation.