Polyacrylonitrile/ferrous chloride composite porous nanofibers and their strong Cr-removal performance

A simple and effective route is presented for the fabrication of polyacrylonitrile (PAN)/ferrous chloride (FeCl2) composite porous nanofibers based on electrospinning technology. The obtained composite nanofibers are amorphous and nanoporous in structure, and 100-300 nm in diameter and 10 m(2) g(-1) in specific surface area. Importantly, such PAN/FeCl2 porous nanofibers have exhibited excellent performance for Cr-removal from a Cr2O72--containing solution in one step. The Cr-removal capability is more than 110 mg Cr/g FeCl2, which is much higher than the previously reported values of the other nanomaterials, as Cr(VI)-removal adsorbents, in addition to the easier separation from solution. This was attributed to the formation of weak coordination bonds PAN center dot center dot center dot Fe(II) in the nanofibers. The coordination bonds on the pore walls and surface not only adsorb the Cr(VI) but also reduce it to Cr(III), alleviating the Cr-induced toxicity. In contrast, the pure PAN nanofibers can not remove Cr, the mixture of PAN nanofibers with FeCl2 powder, and the PAN/FeCl2 cast films only induce insignificant Cr-removal. This study provides an effective route for the development of new environmental remediation materials. The PAN/FeCl2 composite nanofibers could be a good candidate for efficient Cr-removal from wastewater and for the deep-purification of pollutant water.