Efficient removal of lead and copper ions from water by enhanced strength-toughness alginate composite fibers.

In this study, we designed and synthesized an enhanced strength-toughness alginate composite fiber by using graphene oxide as reinforcing filler for removing heavy metal ions from water media. The as-prepared alginate composite fiber exhibits high affinity to Pb2+ ion, and the maximum adsorption capacity for Pb2+ reached 386.2 mg/g, which is higher than the reported Pb2+-sorbent. The prepared round-shaped nanofibers have relatively uniform distribution with a diameter of 400 nm, and the interlaced fibers form porous structure that conducive to the rapid transport of heavy metal ions. Adsorption mechanism analysis shows that the alginate composite fibers combine heavy metals mainly by ion exchange and chemical coordination effects. Owing to the excellent mechanical properties of graphene oxide, the alginate composite fibers can be used repeatedly with minimal loss in performance.