Self-Assembled Zeolitic Imidazolate Framework/Polyimide Nanofibers for Efficient Air Pollution Control

A complex air pollution environment requires filters to be multifunctional. Nanofibrous materials with surface-loaded metal–organic frameworks (MOF-fibers) are reasonable structures for multifunctional air filtration. These materials can not only utilize the network structure of fibers to intercept particulate matter (PM) but also retain the porous structure of the MOFs to adsorb toxic gas. Epitaxial growth methods are commonly utilized to prepare MOF-fibers but are uneconomical and time-consuming. Herein, a facile self-assembly strategy is developed to prepare zeolitic imidazolate framework-polyimide (ZIF-PI) nanofibers with an interconnected network structure and high porosity for air filtration applications. Due to their unique structure, the ZIF-PI nanofibrous membrane exhibited high PM2.5 filtration efficiency and enhanced SO2 adsorption capacity. Moreover, by exploring the morphology evolution of the ZIF-PI nanofibrous membrane, a possible “synergistic effect of hydrophobic and electrostatic force” self-assembly mechanism was demonstrated.