In-situ formation of durable akaganeite (β-FeOOH) nanorods on sulfonate-modified poly(ethylene terephthalate) fabric for dual-functional wastewater treatment

Industrial oily wastewater with dye-pollution is a critical environmental issue for water purification. However, the fabrication of effective and stable materials for oil-water separation and simultaneous degradation of organic contaminants remains a critical challenge. Herein, we report a new process for in-situ formation of akaganeite (beta-FeOOH) nanorods layer on the surface of poly(ethylene terephthalate) (PET) fabric via radiation-induced graft polymerization of glycidyl methacrylate, which is then sulfonated and mineralized. The resultant product is labeled as beta-FeOOH@PET, which exhibits dual purification by demonstrating an effective oil-water separation and organic dyes photodegradation under the illumination of visible light. It provides stable performance even after 1000 wash cycles. The sulfonated layer acts as not only an electronic transport layer to prevent electronhole recombination, but also as an anchored interface for immobilizing beta-FeOOH nanorods on the sulfonated layer via strong covalent bonds. Overall, the superhydrophilicity and underwater superoleophobicity of beta-FeOOH@PET fabric, along with its robustness with a flexible organic substrate and its dual purification function, provide a new insight toward oily wastewater remediation and water purification in large-scale applications.