Ag-coordinated self-assembly of aramid nanofiber-silver nanoparticle composite beads for selective mercury removal

Abstract Metal nanoparticles frequently exhibit good selective extraction ability for Hg(II) in water environment. Here, a kind of Ag-coordination aramid nanofiber-silver nanoparticle composite beads (ANF/Ag) was facilely fabricated using aramid nanofiber (ANF) as the motifs through Ag(I) coordinated self-assembly process. The formation mechanism of ANF/Ag nanoparticle composite beads was established, and the adsorption performances were performed using batch and dynamic experiments, respectively. Ag firstly as promoter coordinated self-assembly of ANF/Ag composite beads, and that can play a role of active sites. ANF/Ag composite showing high adsorption capacities and excellent selectivity towards Hg(II). The adsorption process for Hg(II) followed pseudo-second-order model well, while the dynamic adsorption could be described by the Yoon-Nelson model. Furthermore, adsorption process was a monolayer and chemical adsorption verified by isotherm adsorption. Meanwhile, the maximum adsorption amount of ANF/Ag for Hg(II) was achieved 370.4 mg·g-1. More importantly, ANF/Ag displays remarkable regeneration ability after 5-cycle five cycles of adsorption-desorption. Therefore, this project not only presents an ANF/Ag composite for Hg (II) removal field in environmental pollutions control, but also opens a new design field of ANF material.