Electrospun nanofibrous membrane with vertical binary structure for air filtration and oil/water separation

The escalating global industrialization has precipitated severe environmental crises, particularly from airborne particulate matter (PM) and oily wastewater discharges, which collectively threaten ecosystems and public health. The development of dual-functional separation materials capable of concurrently addressing airborne particulates and oily wastewater constitutes a significant scientific challenge in environmental materials engineering. Herein, based on the sequential electrospinning strategy, we engineered a composite fibrous membrane (CFM) featuring a vertical binary structure with polyacrylonitrile (PAN) nanofiber/net layer and polyvinylidene fluoride (PVDF) bead-on-string fibrous layer for high-performance filtration and superior oil/water mixtures separation. This architecture enables the CFM to achieve 99.35 % PM 0.3 capture efficiency at a low pressure drop (89.83 Pa) and exhibit outstanding durability, maintaining stable filtration efficiency under high particulate loading conditions exceeding 999 μg m −3 . Moreover, attributed to its surface wettability, the CFM demonstrates superb oil/water separation capability, achieving > 95 % separation efficiency with a maximum flux of 6660.66 L m −2 h −1 . Therefore, this work establishes a materials design strategy for developing fibrous membrane with high-performance and charming prospects to address both airborne particulate matter and oily wastewater contamination.