Fabrication of pH-responsive ionic porous organic polymers via ionic liquid mediation for efficient gold recovery from electronic waste

From the perspectives of environmental protection and sustainable development, gold recycling is of paramount importance. This study presents a green synthesis of imine-based porous organic polymers (POPs) using an ionic liquid as the reaction medium. The imine groups within the POPs can be protonated under acidic conditions, transforming them into pH-responsive ionic POPs. Through a synergistic mechanism of electrostatic interaction and in situ reduction, the proposed POP demonstrates an exceptional gold adsorption capacity of 1299.6 mg g⁻ 1 , achieves rapid equilibrium within 15 min, exhibits high selectivity, and maintains excellent reusability over ten consecutive cycles. The adsorption process followed pseudo-second-order kinetic model and the Freundlich isotherm, while thermodynamic analysis confirmed its chemisorption nature. This work not only provides a novel strategy for fabricating ionic POPs but also demonstrates their significant potential for efficient gold recovery from electronic waste.