Novel Disulfide Functionalized Nitrogen-rich Covalent Organic Polymer for Efficient and Recylable Adsorption of Au(III)

Abstract Covalent organic polymers (COPs), as a new type of porous materials, is suitable for selective adsorption and recovery of various metal ions due to its stable skeleton structure, abundant surface functional groups, diverse structure, and large adsorption capacity. According to the acid-base theory, since the unbound lone pair electrons on the S or N atoms are able to form coordination bonds with metal ions, gold ion can form stable metal complexes with negatively charged ligands containing S or N atoms, and thus can be captured from aqueous solutions through coordination and electrostatic interaction. Herein, a novel disulfide functionalized nitrogen-rich covalent organic polymer (S-COP) was synthesized for efficient Au(III) adsorption from aqueous solution. The adsorption equilibrium of the adsorbent could be achieved within 5 h, and the as-synthesized S-COP exhibits an exceedingly high Au(III) uptake capacity of 1506 mg·g− 1. Furthermore, S-COP has satisfactory selectivity and reusability, which is a highlight of adsorption materials.