In-situ growth of molecularly imprinted metal–organic frameworks on 3D carbon foam as an efficient adsorbent for selective removal of antibiotics

Abstract

In recent years, Metal-organic frameworks (MOFs) have attracted extensive attention in the field of adsorption owing to their advantages such as large specific surface area and rich active sites, but the adsorption performance of MOFs is not ideal for the removal of macromolecular organics. In this study, a novel composite material for the efficient and selective removal of norfloxacin (NOR) from wastewater has been successfully prepared via combining molecular imprinting (MI) technology and in-situ growth strategy, in which evenly dispersed MOFs particles are perfectly anchored to three-dimensional porous carbon foam (CF). Owing to more active sites exposed by three-dimensional imprinted holes and the excellent transport properties of CF, the as-prepared MI-MOF/CF exhibits a maximum capacity of 456 mg/g for NOR, which is far superior to that of the pristine MOF. Moreover, the adsorption rate is significantly increased, and the adsorption equilibrium could be reached within 60 min. Interestingly, the selective pharmaceuticals adsorption performance of MI-MOF/CF depends not only on the pore size, but also on the specific recognition ability of the active sites where modified with carboxyl compounds. This work effectively solves the bottleneck encountered by MOFs in the removal of large size antibiotic molecules, and provides a new direction for the design and synthesis of MOFs in the future.