Ionic Modification of Three-Component Covalent Organic Frameworks with Antibacterial Function for Efficient and Selective Gold Recovery

Developing multifunctional adsorbents with exceptional capture performance and outstanding antibiofouling activity is of great significance for the recovery of gold. However, most of the reported materials only have a single adsorption function, which restricts their practical application for gold extraction from complex matrices. Herein, we construct a series of three-component covalent organic frameworks (COFs) with good antibacterial performance for the extraction of gold. All the obtained COFs show high adsorption capacities over 1250 mg·g–1 for gold, which may be attributed to the high specific surface area, regular pore structure and abundant binding sites. In particular, the optimized materials COF-TPTD-DHTA-TAB gives excellent adsorption capacity (2884 mg·g–1), ultrafast adsorption kinetics (60 min) and high distribution coefficient (Kd > 4 × 105 mL·g–1). More importantly, good sterilization performance is observed on both COF-TPTD-DHTA and COF-TPTD-DHTA-TAB under visible light irradiation. This work provides a paradigm to develop ionic three-component COFs with antibacterial activity for gold recovery.