Dual-functional Cu2O-Fe3O4 Fenton nanocatalyst integrating pollutant degradation and magnetic microplastic separation in wastewater treatment

초록

Modern industrial wastewater contains a complex mixture of low-molecular-weight organic contaminants and physically persistent microplastics, both of which are difficult to remove due to their chemical stability, structural diversity, and toxicity. Here, we report Cu2O-anchored Fe3O4 mesocrystalline nanoparticles (CFNPs) as a dual-functional Fenton nanocatalyst that integrates oxidative degradation and magnetic separation within a single platform. The synergistic redox cycling of Fe2+/Fe3+ and Cu+/Cu2+ in CFNP enhances hydroxyl radicals (center dot OH) generation from hydrogen peroxide, as confirmed by radical scavenger tests and Michaelis-Menten analysis (nu(max) =2.67 x 10(-7) M/s). Under optimized conditions, methylene blue is degraded by similar to 91 % within 30 min. Three representative antibiotics, tetracycline, ciprofloxacin, and sulfamethoxazole, follow pseudo-first-order kinetics with rate constants of 3.96 x 10(-2), 2.93 x 10(-2), and 8.51 x 10(-3) min(-1), respectively, yielding >90 % removal at 80-240 min. In parallel, polyethylene terephthalate (PET) microplastics undergo Fenton-induced surface oxidation, where center dot OH-induced ester bond cleavage introduces additional carboxyl and hydroxyl groups onto the polymer surface. FT-IR and XPS analyses confirm the formation of oxygen-containing functionalities and Cu-carboxylate coordination, indicating strong interfacial binding between CFNPs and oxidized PET. These surface modifications promote CFNP adhesion and enable magnetic separation of PET microplastics with similar to 90 % mass removal efficiency after 24 h. The combined oxidation-separation behavior demonstrates that CFNPs function as a versatile, magnetically recoverable nanocatalyst for treating chemically recalcitrant organic molecules and physically resistant microplastics, providing a promising proof-of-concept for next-generation advanced oxidation processes in water remediation.

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