Removal and reuse of Ag nanoparticles by magnetic polyaniline/Fe3O4 nanofibers

For the treatment of wastewater containing Ag nanoparticles (NPs), PANI/Fe3O4 nanofibers were firstly prepared by a novel self-assemble. And then, the efficiency for the removal of Ag NPs from wastewater was investigated. The magnetic performance of PANI/Fe3O4 nanofibers could be optimized by adjusting the pH of the self-assemblied system. Under pH of 3, the as-prepared nanofibers exhibited the highest magnetism and also displayed good efficiency (> 12 mg g(-1)) for the removal of Ag NPs. Importantly, the resulted product (PANI/Fe3O4/Ag composite) could act as a catalysis for cleaning durable pollutant, 4-nitrophenol. After 10 cycles, only slight decrease in rate constant was found, indicating excellent reusability. Those approaches provide a new way to merge the recovery of Ag NPs as pollutants and reuse of recovered Ag NPs as recyclable material for environmental remediation.