Electrospinning preparation of nylon-6@UiO-66-NH2 fiber membrane for selective adsorption enhanced photocatalysis reduction of Cr(VI) in water

The environmental problem caused by Cr(VI) need to be solved urgently. Fiber membranes have been widely utilized for pollutants removal owing to their high surface area and easy recovery property. Inspiredly, a nylon-6@UiO-66-NH2 fiber membrane was prepared using electrospinning and subsequent in-situ crystal growth process. In the process, UiO-66-NH2 crystals grew on the nylon-6 fiber uniformly and continuously through in-situ solvothermal treatment. The unique structure exhibits selective adsorption enhanced photocatalysis performance towards Cr(VI) reduction under visible light irradiation. The nylon-6 fiber resists aggregation of UiO-66-NH2 crystals and provides nitrogen-containing functional groups for the composite membrane, which shows selectively high adsorption capacity for Cr(VI) (202.79 mg·g−1) based on electrostatic and chelation interactions. Such excellent adsorption behavior is beneficial for photocatalytic reduction of toxic Cr(VI) into Cr(III). More importantly, the photocatalytic capacity of nylon-6@UiO-66-NH2 fiber membrane for Cr(VI) is 27.1 mg·g−1 of UiO-66-NH2, almost twice that of pure UiO-66-NH2 powder (15.5 mg·g−1), exhibiting selective adsorption enhanced photocatalysis performance. This work not only offers a novel strategy for in-situ fabrication of polymer@MOF composite membrane but also gives insight into adsorption enhanced photocatalysis Cr(VI) reduction behavior.