PA6@FexOy nanofibrous membrane preparation and its strong Cr (VI)-removal performance

Removal of hexavalent chromium Cr (VI) from water is a key problem in environmental remediation. In this work, PA6@FexOy composite nanofibrous membrane was fabricated by electrospinning technique combined with hydrothermal strategy. Scanning electron microscopy (SEM), X-ray diffraction (XRD) and transmission electron microscopy (TEM) revealed that the iron oxides nanoparticles on the surface of membrane were amorphous structure. The Cr (VI) removal experiment showed that the obtained PA6@FexOy nanofibrous membrane exhibited excellent performance for the removal of Cr (VI). The adsorption capacity can reach 150 mg Cr/g nanofibrous membrane, which is much higher than the previously reported values of some nanomaterials. The adsorption isotherm research showed that the adsorption of Cr onto the membrane was Freundlich adsorption, indicating that multi-layer adsorption occurred on the nanofibrous membrane. X-ray photoelectron spectroscopy (XPS) characterization proved that Cr (VI) removal mechanism mainly contained electrostatic adsorption and redox reaction. Electrostatic adsorption can adsorb Cr (VI) and redox reaction could reduce Cr (VI) to Cr (III), which is much less toxic. Therefore, the PA6@FexOy composite nanofibrous membrane could be a good candidate for removing Cr (VI) from wastewater, and the study provides a simple and effective route for the development of new environmental remediation nanomaterials.

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► Iron oxides nanoparticles were grown on the surface of PA6 nanofibers.
► The adsorption process for Cr (VI) was Freundlich adsorption.
► The adsorption capacity can reach 150 mg Cr/g composite nanofibrous membrane.