Synergistic Microplastics Capture and Bacterial Inhibition by a Cationic COF‐Reinforced Chitosan/Tannic Acid Aerogel

ABSTRACT Microplastics, an emerging class of pollutants, have garnered significant attention in recent years due to their large specific surface area, capacity to adsorb other contaminants, and persistent nature, which collectively pose serious risks to ecosystems and human health. In this study, a cationic HTA‐EB covalent organic framework (COF) was synthesized via a solvothermal method and subsequently hybridized with low‐cost natural polymers‐chitosan and tannic acid. After freeze‐drying, a monolithic ionic COF‐based aerogel was obtained. This strategy not only reduced material cost but also overcame the limitations associated with powdered COFs, offering a simple, rapid, and convenient fabrication route ideal for microplastic removal. The aerogel effectively captures microplastics through synergistic electrostatic, π‐π, and hydrogen‐bonding interactions. The maximum adsorption capacities of the iCOF aerogel were 550.73 mg g ⁻¹ for polyethylene terephthalate (PET), 341.74 mg g ⁻¹ for polystyrene (PS), and 209.32 mg g ⁻¹ for polycarbonate (PC). The material effectively removed microplastics in real water samples while exhibiting antibacterial and antifungal activity, collectively supporting its potential for long‐term practical remediation by preventing biofouling.