Engineering ion-framed porous organic polymer for synergistic high-capacity adsorption and ultra-trace recovery of gold.

Developing advanced functional adsorbents capable of selectively recovering gold from electronic waste (e-waste) and enriching trace amounts of gold from seawater is a critical technical imperative for advancing a sustainable economy. In this study, a cationic pyridine porphyrin-based porous organic polymer (Pyd-PPOPs-Br) was rationally designed and presented via a one-pot bottom-up approach by integrating cationic pyridine-based building blocks with pyrrole. The incorporation of positively charged pyridine sites and redox-active porphyrin rings conferred Pyd-PPOPs-Br with an ultrahigh gold recovery capacity of 3.79 g/g, along with exceptional efficacy in concentrating trace and ultra-trace gold from both deionized water and seawater matrices. The exceptional adsorption performance of Pyd-PPOPs-Br was elucidated through comprehensive characterization and density functional theory (DFT) calculations. In practical validation, the material selectively sequestered 99.98 % of Au (III) ions from simulated e-waste leachates. Furthermore, a laboratory-scale fixed-bed adsorption device packed with Pyd-PPOPs-Br demonstrated comparable separation efficiency, highlighting its strong potential for scalable and long-term operation. This study establishes a foundational strategy for precious metal recovery using ion-framed porous organic polymers (POPs) and offers valuable design insights for developing functionally tailored adsorbents to address challenges in resource sustainability.