Excellent copper(II) removal using zero-valent iron nanoparticle-immobilized hybrid electrospun polymer nanofibrous mats

We fabricated hybrid nanofibrous mats by electrospinning a polyacrylic acid (PAA)/polyvinyl alcohol (PVA) mixture polymer solution, with multiwalled carbon nanotubes (MWCNTs) incorporated into the nanofibers to enhance their mechanical durability. The mats were further immobilized with zero-valent iron nanoparticles (ZVI NPs) as an active agent for potential environmental applications. Herein, we systematically evaluated the interaction between Cu(II) ions and these MWCNT-reinforced ZVI NP-containing nanofibrous mats in aqueous solutions. Both equilibrium and kinetic behaviors were experimentally assessed, and the influential factors such as pH, contact time, and solution ionic strength were examined. The results indicate that Cu2+ chemisorption occurs via chemical reduction and deposition on the ZVI NP surfaces to form Fe/Cu alloy. The uniform ZVI NPs contained in the hybrid nanofibers offer great specific surface areas that enable very effective, high capacity and strong sorption of Cu(II) ions. The study suggests that the hybrid mats immobilized with ZVI NPs can be a useful material for the removal of Cu(II) ions, and likely many other heavy metal ions, from water, and provides a basis for further development.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► The ZVI NP-immobilized nanofibers enable very effective sorption of Cu (II) ions. ► MWCNTs incorporated in the nanofibers did not compromise the Cu(II) removal ability. ► Chemisorption of Cu2+ occurs onto the ZVI NP-immobilized hybrid nanofibers. ► The ZVI NP-containing nanofibers may be useful for removal of other heavy metal ions.