Mg‐MOF‐74@PAN Nanofibrous Membranes: Synergistic Purification of Trace Formaldehyde and Particulate Matter

The rapid removal of trace formaldehyde and particulate matter (PM) from indoor environments via adsorption and filtration remains a significant challenge. Herein, a series of MOFs@PAN composite membranes with dense adsorption sites and enhanced electrostatic interactions are engineered for efficient formaldehyde capture and PM filtration. The 72%-Mg-MOF-74@PAN membrane demonstrated a remarkable HCHO adsorption capacity of 36.39 mg g^-1 (1 ppm, 303 K) and a breakthrough adsorption capacity of 106.11 mg g^-1 (10 ppm, 298 K), surpassing that of commercial activated carbon (1.23 mg g^-1) and ZIF-67@ANF (MOFs, 5.31 mg g^-1). The superior trace HCHO adsorption originates from strong electrostatic interactions between unsaturated Mg clusters and HCHO, coupled with densely distributed adsorption sites within the framework. Furthermore, the 72%-Mg-MOF-74@PAN membrane exhibited a particle filtration efficiency of over 99.5% for PM_0.3. The PM_0.3 capture mechanism synergistically integrated passive structural diffusional deposition mediated by the ultrafine PAN fibers (0.25 µm) and proactive electrostatic entrapment driven by surface hydroxyl groups and unsaturated metal sites. This research underscores the exceptional performance of Mg-MOF-74@PAN membranes in improving indoor air quality, efficiently eliminating formaldehyde and proficiently filtering PM_0.3 particles.