Nanofibrous spherical cage mimicking a ball of pearl necklaces for super capture of heavy metal ions

Abstract

Late and poor responses in the initial stages of large-scale heavy metal leakage accidents have long-term adverse effects on nature and humans. Fast and high-performance separation technology with a low pressure drop is thus essential for wide-area water decontamination. Herein, we demonstrate a strategy to design and synthesize a millimeter-sized spherical separation material that mimics a ball of pearl necklaces with a hierarchically porous 3D-structure, which provides an amine-rich surface for heavy metal ion adsorption and a large void space for the crystal growth of adsorbed ions. The separation material shows excellent sequestration capacity for heavy metal ions, with its entire pores becoming filled with heavy metal crystals through the sequential adsorption and crystal growth of heavy metal ions. Our work represents the most pragmatic way possible to address wide-area heavy metal leakage accidents using a scalable water treatment column packed with spherical separation materials that achieves a very low pressure drop.