Ultrafine Nanofiber-Based Membrane with Rational Hierarchical Networks for Efficient and High-Flux Air and Water Purification

With the accelerated development of global industrialization, environmental issues, such as airborne and water pollution caused by suspended solid particulate matter (PM) seriously endanger ecosystems and human health. Fibrous filtration and separation membranes provide an effective approach to pollution treatment, yet they still face challenges in efficient and high-flux purification of highly permeable ultrafine particles. Herein, an ultrafine nanofiber-based membrane with rational hierarchical networks is designed for both air and water filtration. Through the proposed jet branching electrospinning strategy, a multiscale fiber membrane consisting of ultrafine nanofibers, medium fibers, and coarse submicron fibers is prepared. It possesses the merits of ultrafine fiber diameter, ultralow pore size, high specific surface area, and unique hybrid structure. Benefiting from these features, the obtained multiscale fibrous filter shows superior PM_0.3 air filtration performance (99.96% PM_0.3 removal, low pressure drop of 89 Pa) and water filtration capacity (ultrafine particle rejection efficiency of 99.50%, water flux of 9028.84 L m⁻² h⁻¹). Moreover, the controllable structure of a multiscale fiber filter also endows itself with stable and durable filtration capacity. This work may provide meaningful references for the development of high-performance filtration and separation materials.

Graphical abstract