Preparation Of Electrospinning Composite Nanofibers And Its Application In Cr-removal

With the rapid development of global economy, heavy metal pollution has been aworld-wide problem and attracts increasing attention from all the countries andregions. Among them, hexavalent chromium (Cr (Ⅵ)) is extremely harmful becauseof its high solubility, toxicity and non-biodegradable nature, endangering people’s lifeand health. Therefore，the removal of Cr (Ⅵ) from a contaminated aqueous solution isa major global issue.In this paper, based on electrospinning technique combined with chelationreactions and pyrolytic strategy, the simple and eiffcient routes are presented tofabricate three kinds of composite nanoifbers. Fourier transform infrared spectroscopy(FTIR)，scanning electron microscopy (SEM)，X-ray diffraction (XRD) andtransmission electron microscopy (TEM) were applied to characterize the structureand morphology of the products:1. Prepared the homogeneous solution of PA6andIA to electrospin PA6@IA nanoifbers，and then prepared the PA6@FexOy compositenanoifbers by hydrothermal reaction, with petals shape nano ferric oxide crystalsgenerated on PA6ifbers.2. Taking electrospinning PA6ifbers as substrate？ preparedPA6@FexOy composite nanoifbers by chelation with ferric salt and pyrolysis,resulting in granular nano ferric oxide crystals generated on the in PA6nanoifbers.3.Prepared PA6/chitosan nanoifbers with uniform two-dimensional ultraifne networksbased on electrospinning, then chelation and pyrolytic reaction is presented for thefabrication of iron oxides loaded nanoifbrous membranes, revealing that dense FexOynanoparticles loaded on the surface of composite nanoifbers.And then their Cr (Ⅵ) removal performances ware studied. The Cr-removal experiment showed that the prepared nanoifbers exhibited outstanding Cr-removalperformance: the adsorpiton process belonged to Freundlich adsorption model, andthe kinetics of the adsorption followed the pseudo-second-order model. Theadsorpiton mechanism includes two processes, adsorpiton (including both Cr (Ⅵ) andCr (Ⅲ) species) and reduction. Therefore，the work not only provides a highlyeiffcient adsorbent to remove hexavalent chromium from waste water, but also offersa simple and eiffcient new method for environmental restoration ifeld.