Thiol-yne click postsynthesis of imidazole-functionalized cyclodextrin microporous organic network: A remarkable adsorbent for sulfonamide antibiotics

Abstract

Sulfonamides (SAs) are widely used broad-spectrum antibiotics for treating infections. However, their inevitable residues pose serious threats to human health and agroecosystems. Hence, reasonable design and synthesis efficient adsorbents to remove residual SAs from the environment are crucial and highly desired. In this study, a novel imidazole-functionalized cyclodextrin-based microporous organic network (α-CD-MON-BZ) was designed and synthesized through the specific thiol-yne click post-modification for the efficient removal of SAs. The prepared α-CD-MON-BZ exhibited ultrafast adsorption kinetics (<3 min) and an exceptionally high saturation adsorption capacity (571.4 mg/g) for sulfamethoxypyridazine (SMP). This capacity was much higher than those of other reported adsorbents. Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and density functional theory calculations revealed that the adsorption process involves hydrophobic, π–π, hydrogen bonding, host–guest, and electrostatic interactions. Furthermore, α-CD-MON-BZ exhibited favorable reusability and selectivity. This study introduces a new method to construct novel functionalized CD-MONs for highly efficient SAs removal and promotes the design and applications of such materials in contaminant removal.