Core-shell heterostructure ZnO@ZIF-8 nanorods anchored within PTFE fibrous networks for the durable removal of cationic dye and Cu2+ in wastewater

Highly diffuse cationic dyes and copper ions are normal pollutants in dye wastewater and pose a potential ecological risk, threatening human health. However, current MOF-based fibrous composites usually scarify their stability of active sites for photocatalytic reaction, which inevitably causes nondurable removal of these diffuse particles. Here, an in situ growth strategy was proposed to fabricate robust core-shell heterostructure of ZnO@ZIF-8 nanorods which were anchored within polytetrafluoroethylene (PTFE) micro-scale fibers by the solution-blowing spinning (SBS) technique to achieve ZnO@ZIF-8/PTFE hierarchical fibrous networks (ZZP-HFN). It presents superior degradation of cationic dyes (over 97%) and durable decompose stability of more than 20 cycles, and prominent adsorption capacity for copper ions (86.53 mg/g). Moreover, contrast to the existing MOF-based fibrous membranes, ZZP-HFN exhibits the self-cleaning performance on account of its stable composite structure between ZnO@ZIF-8 nanorods and PTFE fiber. The cationic dyes removal of ZZP-HFN from wastewater is attributed to the synergistic effect of adsorption and photocatalytic ability. This work provides an insight to design advanced MOF-based composites with durable photocatalytic performance for dye wastewater purification.