Highly Selective Recovery of Gold by In Situ Magnetic Field‐Assisted Fe/Co‐MOF@PDA/NdFeB Double Network Gel

Abstract There are enormous economic benefits to conveniently increasing the selective recovery capacity of gold. Fe/Co‐MOF@PDA/NdFeB double‐network organogel (Fe/Co‐MOF@PDA NH) is synthesized by aggregation assembly strategy. The package of PDA provides a large number of nitrogen‐containing functional groups that can serve as adsorption sites for gold ions, resulting in a 21.8% increase in the ability of the material to recover gold. Fe/Co‐MOF@PDA NH possesses high gold recovery capacity (1478.87 mg g −1 ) and excellent gold selectivity (Kd = 5.71 mL g −1 ). With the assistance of an in situ magnetic field, the gold recovery capacity of Fe/Co‐MOF@PDA NH is increased from 1217.93 to 1478.87 mg g −1 , and the recovery rate increased by 24.7%. The above excellent performance is attributed to the efficient reduction of gold by FDC/FC + , Co 2+ /Co 3+ double reducing couple, and the optimization of the reduction reaction by the magnetic field. After the samples are calcined, high‐purity gold (95.6%, 22K gold) is recovered by magnetic separation. This study proposes a forward‐looking in situ energy field‐assisted strategy to enhance precious metal recovery, which has a guiding role in the development of low‐carbon industries.