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

Abstract

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 m2 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⋯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.