Facile synthesis of multifunctional acylhydrazone-based covalent organic polymer for rapid removing Hg(II) and Ibuprofen from water

Covalent organic polymers (COPs) are one of the most efficient and cost-effective adsorbents for removing heavy metals and antibiotics. Herein, three novel COPs were synthesized by a unique aldehyde and three hydrazine amines possessing varying numbers of acylhydrazone groups. And the H-COP-3 which is rich in acylhydrazone bonds gave the highest adsorption capacity (639.751 mg g−1) among the three materials on removing Hg(II) and equilibrium within 15 min, attributing to the strong affinity between acylhydrazone and Hg(II). Owing to the existence of hydrogen bonding and π-π stacking in the H-COPs and ibuprofen (IBP), the adsorption capacity of IBP on both new adsorbents was more than 230 mg g−1 showing no obvious disparity. Furthermore, H-COPs exhibit high stability over a wide pH range and still possess considerable Hg(II) and IBP adsorption capacity after multiple cycles. Our results reflect the great potential of these acylhydrazone-based COPs for environmental remediation.