Silk‐Wastes‐Derived Porous Silk Fibroin Aerogel Embedded With Nano‐Sized Fe 2 O 3 for Efficient Removal of Tetracycline Hydrochloride

ABSTRACT The efficient removal of antibiotics from aquatic environments is crucial to safeguard both ecosystems and human health. Herein, silk fibroin/Fe 2 O 3 (SF/Fe 2 O 3 ) aerogel was fabricated from silk wastes and nano‐sized Fe 2 O 3 powders through freeze‐casting and vacuum freeze‐drying strategy. The resulting SF/Fe 2 O 3 aerogel showed three‐dimensional honeycomb‐like porous structures. Benefiting from its porous structures and abundant active sites, SF/Fe 2 O 3 aerogel exhibited outstanding adsorption performance toward tetracycline hydrochloride (TCH), enabling high‐value recycling of silk wastes. Systematic studies on the effects of Fe 2 O 3 weight percentages, initial TCH concentrations, adsorbent dosages, and pH values revealed that the aerogel achieved a high removal efficiency of 87.47% at pH 5. The adsorption kinetic and isothermal analyses demonstrated that the adsorption process of SF/Fe 2 O 3 aerogel followed a pseudo‐first‐order adsorption kinetic model with R 2 = 0.9726 and a Freundlich model with R 2 = 0.9682, suggesting spontaneous heterogeneous multilayer physisorption. The adsorption mechanism was dominated by electrostatic interactions, hydrogen bonding, π–π interactions, cation bridging, and hydrophobic forces between SF/Fe 2 O 3 aerogel and TCH. This study provides a green and sustainable route for the utilization of silk wastes and offers a promising strategy for antibiotic removal in aquatic environments.