Self-Assembly of a Metal–Phenolic Sorbent for Broad-Spectrum Metal Sequestration

Metal contamination of water bodies from industrial effluents presents a global threat to the aquatic ecosystem. To address this challenge, metal sequestration via adsorption onto solid media has been explored extensively. However, existing sorbent systems typically involve energy-intensive syntheses and are applicable to a limited range of metals. Herein, a sorbent system derived from physically cross-linked polyphenolic networks using tannic acid and ZrIV ions has been explored for high-affinity, broad-spectrum metal sequestration. The network formation step (gelation) of the sorbent is complete within 3 min and requires no special apparatus. The key to this system design is the formation of a highly stable coordination network with an optimized metal–ligand ratio (1.2:1), affording access to a major fraction of the chelating sites in tannic acid for capturing diverse metal ions. This system is stable over a pH range of 1–9, thermally stable up to ∼200 °C, and exhibits a negative surface charge (at pH 5...