Thiol-functionalized PCN-222 MOF for fast and selective extraction of gold ions from aqueous media

With the growing demand of gold for research laboratories and industrial technologies, there is high needed to extract gold from related waste other than natural resources. Herein, we designed a novel adsorbent denoted as PCN-222-MBA (Thiol-functionalized PCN-222), by functionalizing Zr-6-nodes of PCN-222 (PCN = Porous Coordination Network) with 4-mercaptobenzoic acid (MBA) through solvent-assisted ligand incorporation (SALI) approach for selective and facile extraction of gold ions from aqueous media. The mesoporous MOF was characterized by different techniques. The performance of PCN-222-MBA as solid adsorbent was assessed under batch conditions, with significant parameters studied and optimized. The maximum adsorption capacity of the respective adsorbent was 714.3 mg/g at pH 6.1 and 1 min. PCN-222-MBA exhibited high affinity for Au(III) than other coexisting ions and could be regenerated at least six cycles. Gold ions were also extracted and determined in real samples.

Automated summary

A novel adsorbent PCN-222-MBA was designed to selectively extract gold ions from aqueous media, exhibiting high affinity for Au(III) and the ability to be regenerated for at least six cycles. The maximum adsorption capacity reached 714.3 mg/g at pH 6.1 and 1 min.