Crown ether-based hypercrosslinked porous polymers for gold adsorption

With the over-exploitation of global resources, the recycling of gold becomes an urgent task to be solved. In this regard, design of stable adsorbents with low cost and large capacity is meaningful for the secondary utilization of resources. Herein, to obtain the efficient adsorbents, dibenzo-18-crown-6 (DB18C6) and dibenzo-24-crown-8 (DB24C8) were cross-linked for the first time by Friedel–Crafts reaction to synthesize crown ether-based hypercrosslinked porous polymers, named DB18C6-HCP and DB24C8-HCP, respectively. These adsorbents exhibit high porosity, good stability, and outstanding gold adsorption selectivity. Notably, DB18C6-HCP exhibits a high gold uptake capacity with 1667 mg g−1. Furthermore, gold ions are in situ reduced into gold nanoparticles by DB18C6-HCP and DB24C8-HCP along with gold ion adsorption process. In short, we have confirmed the potential of porous organic polymers for the adsorption of gold, and provided a powerful reference for the recovery and reduction of gold.