An all-in-one platform: Core-shell Fe3O4@ZIF-8 for tetracycline removal via coupled adsorption and Fenton-like catalysis

The tetracycline (TC) contamination in water demands innovative ways that combine adsorption with degradation. To this end, this study develops a core-shell magnetic Fe 3 O 4 @ZIF-8 composite, which functions as a synergistic platform for adsorption and Fenton-like catalysis. The material leverages the high surface area of ZIF-8 (688.28 m 2 /g) and the magnetic responsiveness of Fe 3 O 4 (23.05 emu/g) for easy separation. It exhibits an exceptional TC adsorption capacity of 613.5 mg/g, with kinetics and isotherms best described by pseudo-second-order and Freundlich models, respectively, indicating a chemisorption-driven, multilayer process. The primary mechanisms were identified as π-π interactions, coordination, and hydrogen bonding. Furthermore, the embedded Fe 3 O 4 core enables a Fenton-like reaction with H 2 O 2 , effectively degrading the adsorbed TC. The composite demonstrated remarkable stability, retaining over 80% of its adsorption capacity after five cycles. This work presents a robust and recyclable platform for the integrated adsorption and catalytic degradation of antibiotics.