A novel PAN/GO electrospun nanocomposite fibrous membranes with rich amino groups for highly efficient adsorption of Au(III)

Abstract

The wastewater containing Au(III) is directly discharged into the natural environment, resulting in a serious waste of resources and pollution of water environment. Therefore, it has profound significance to efficiently remove and recover Au(III) from industrial wastewater. Hyperbranched polyethyleneimine (HPEI), as a non-toxic polymer, rich in primary and secondary amine groups, which have strong affinity for metal ions. However, the application of HPEI as an adsorbent in water system is limited by the fact that it is water-soluble and difficult to separate and recover. In this study, using graphene oxide (GO) grafted with HPEI as additive and polyacrylonitrile (PAN) as matrix, PAN/GO-HPEI electrospun nanocomposite fibrous membranes were synthesized by electrospinning, and then grafted with HPEI by chemical graft reaction to obtain HPEI-g-PAN/GO-HPEI electrospun nanocomposite fibrous membranes, which were employed as adsorbent to adsorb Au(III) in aqueous solution. Benefitting from the existence of rich amino groups in the HPEI-g-PAN/GO-HPEI, the HPEI-g-PAN/GO-HPEI had highly efficient adsorption for Au(III) and the maximum adsorption capacity was 2893.33 mg·g−1. Significantly, the adsorbed Au(III) could be reduced to Au(I) and irregular flakes and granular Au elemental attached to the adsorbent in the adsorption process. Moreover, the HPEI-g-PAN/GO-HPEI had excellent adsorption selectivity for Au(III). Therefore, the HPEI-g-PAN/GO-HPEI has potential applications as a promising adsorbent for highly efficient recovery of Au(III) in wastewater.