Anion-π Interactions on Functionalized Porous Aromatic Cages for Gold Recovery from Complex Aqueous with High Capacity.

High capacity, selective recovery and separation of precious metals from complex aqueous solutions is essential but remains a challenge in practical applications. Here, we prepared a thiophene-modified aromatic porous organic cage (T-PAC) with high stability for precise recognition and recovery of gold. T-PAC exhibits an outstanding gold uptake capacity of up to 2260 mg/g with fast adsorption kinetics and high adsorption selectivity. It's also used to selectively recover gold from a variety of complex aqueous solutions in a stable and efficient manner. The theoretical calculations and dedicated experiments suggest that anion-π interactions between the [AuCl4]- and TFP fractions on T-PAC cooperated with S/N boning and redox effects play the decisive role in the highly efficient gold recovery performance.