Robust Hierarchical Flower-Like ZnO/PAN Nanofibrous Membranes for Efficient Air Filtration

Developing an inhibition air filter that can efficiently filter fine particulate matter and maintain low-pressure resistance still faces significant challenges. A rough-surfaced PAN composite nanofibrous membrane loaded with flower-like ZnO was successfully fabricated via blend electrospinning and hydrothermal synthesis. Compared to PAN nanofibrous membranes (PAN NFMs) and commercial ZnO/PAN NFMs, flower-like ZnO/PAN NFMs achieved 99.99 and 99.59% filtration efficiencies for PM10–2.5 and PM0.3, respectively, at a low pressure drop of 88 Pa. It demonstrated outstanding filtration stability under varying airflow intensities and during a 300 min long-term test, with antibacterial rates of 99.3 and 98.5% against E. coli and S. aureus, respectively. SEM, AFM, and BET analyses revealed that the wrinkled fiber surfaces and flower-like ZnO synergistically enhanced PM diffusion and interception effects by increasing surface roughness and specific surface area. Additionally, airflow channels formed by the transition flow in fine-diameter fibers and flower-like cavities significantly mitigated pressure drop elevation.