Two birds with one stone: Co/Fe bi-MOFs@PAN nanofiber aerogel films for efficient degradation of organic contaminants and separation of emulsions

Abstract

The development of materials for effective treatment of complex water is in high demand, but remains challenging. In this study, a multifunctional Co/Fe bi-MOFs decorated polyacrylonitrile nanofiber aerogel film was rationally designed and fabricated using a combination of electrospinning, freeze-drying, and subsequent in-situ hydrothermal methods. The NAF has a hierarchically porous architecture and is capable of degrading dyes and separating oil-in-water emulsions. The results demonstrate that the NAF has outstanding catalytic performance in peroxymonosulfate activation for methylene blue degradation, with a degradation efficiency of above 99.74 % and a reaction rate of 0.0911 min−1 within 40 min. Electron paramagnetic resonance analysis and quenching tests revealed that sulfate radical, hydroxyl radical, singlet oxygen, and superoxide radical are all involved in the degradation of MB and sulfate radical is the major reactive species. Furthermore, the composite NAF can separate oil-in-water emulsions with superior efficiency of above 99.85 % and desirable flux higher than 422 L·m−2·h−1, due to its hierarchically porous architecture and remarkable wettability. The composite NAF displays robust reusability and stability for long-term use. This study demonstrates the benefits of integrating advanced oxidation processes with membrane technology and provides novel perspectives into the evolution of multifunctional materials for complex wastewater treatment.