Ligand removal and metal exchange tailoring of HP-MOFs for gold recovery from electronic waste

Traditional metal–organic frameworks, characterized by their micropore-dominated structures, suffer from severe pore channel blockage during gold ion recovery due to the aggregation of gold nanoparticles, significantly reducing the utilization rate of adsorption sites. To address this issue, we developed hierarchically porous MOFs through ligand removal and metal exchange strategies, precisely installing adsorption sites within meso/macropores to effectively prevent pore obstruction by adsorbed-reduced gold particles. Subsequent Metal substitution further enhanced the material’s aqueous stability, enabling retention of 93 % adsorption capacity after 5 cycles while preserving the precisely engineered pore structure. The functionalized HP-MOF-5/DU achieves an ultrahigh Au(III) capacity of 1566 mg/g, rapid kinetics, and exceptional selectivity. Practical validation demonstrates 85 % gold recovery from real electronic waste leachates, with calcination yielding gold particles of 23.7 K purity. Through rational regulation of pore channel structures at adsorption sites, we have significantly enhanced the material’s Au(III) adsorption performance, pioneering a novel direction for the design of reducible metal-targeted adsorbents.