On-demand switchable superamphiphilic nanofiber membrane reinforced by PET braided tube for efficient wastewater purification and photocatalytic regeneration

Nanofiber membrane is regarded as one of the ideal candidates for complex wastewater purification. However, the membrane fragility, fouling and dull wettability limits its widespread application. In this work, a hybrid zeolitic imidazolate framework-8 @zinc oxide nanorod decorated poly (vinylidene fluoride) tubular nanofiber membrane (ZIF-8 @ZnO/PVDF-TNM) was developed based on a polyester braided tubular reinforcement substrate. The hybrid membrane was fabricated by ZnO seeds conversion, ZnO nanowire growth via hydrothermal technique and ZIF-8 deposition using self-template scarifying method. The resultant ZIF-8 @ZnO/PVDF-TNM possesses enhanced photocatalytic capacity for pollutants removal and superamphiphilicity or under-liquid superamphiphobicity depending on its nanoarchitecture. In virtue of well-grown ZIF-8 @ZnO nanorods, the membrane exhibits a commendable permeation ability (784 and 865 L·m−2·h−1 for water and oil, respectively) under gravity operation, superior oil/water separation efficiency (> 99.9%) for various emulsions. Moreover, it can achieve high-efficient pollutants degradation, self-cleaning and membrane regeneration by solar light irradiation. This study demonstrates a new approach to fabricate the switchable superamphiphilic nanofiber membrane for water remediation and membrane regeneration.