Preparation of molecularly imprinted metal-organic frameworks for the selective removal of norfloxacin by an in-situ self-assembly template strategy.

Abstract As a new type of material, metal-organic frameworks (MOFs) have several advantages, including a large specific surface area, high porosity, and adjustable pore structure. However, due to their small pore size, microporous MOFs are not conducive for the diffusion and mass transfer of macromolecular compounds, which limits their application in the adsorption and removal of these compounds. In this study, molecularly imprinted MOFs (MOF-MIPs) were synthesised by in-situ self-assembly strategy using NH2-MIL-101 as a foundational MOF and norfloxacin (NOR) as the template molecule, and used in the adsorption of NOR. Various characteristics of the materials were determined, and it was found that the introduction and elution of the template molecules did not destroy the structure of the original MOFs. Additionally, according to the dynamics and isotherm fitting results, the adsorption rate of MOF-MIPs was over three times higher than that of the original MOFs, and the maximum ideal adsorption capacity increased by nearly three times to 651 mg/g at 293 K. Furthermore, the selective adsorption experiment results indicated that the MOF-MIPs had excellent selective adsorption capacity, which was mainly attributed to the specific ability of MOF-MIPs three-dimensional imprinted holes to recognise template molecules, in addition to the screening effect of the MOFs’ pore sizes. This study provides a feasible strategy for the application of MOFs in the high-efficiency selective adsorption and removal of macromolecules, such as antibiotics.