The massive discharge of industrial waste gas and oily wastewater seriously harms the ecological environment and human health. It still remains a tremendous challenge for researchers to develop robust functional materials to control air pollution and purify oily wastewater in actual harsh environments. Herein, a polyacrylonitrile (PAN)@TiO₂/poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP)@SiO₂ nanofibrous (PTPS_NF) Janus membrane was successfully prepared by sequential electrospinning strategy. Due to its unique bi-layer structure and synergistic effect of multiple components, the composite filter could overcome the trade-off effect of high filtration efficiency and low air resistance and realized filtration efficiency of 99.7 % (PM_0.3 removal) with a pressure drop of 27 Pa. The combination of the hygroscopic PAN@TiO₂ layer and the self-cleaning PVDF-HFP@SiO₂ layer endowed the Janus filter obvious advantage in the field of personal protection. Meanwhile, the PTPS_NF membranes still remained excellent air filtration performance after strong acid/alkali treatments. Furthermore, due to its asymmetric wettability, the PTPS_NF Janus membranes emerged switchable oil/water separation ability, which could efficiently separate different oil/water mixtures and emulsions with high flux and separation efficiency. Therefore, the robust functional Janus nanofibrous filter offers fascinating application prospects in harsh environmental air filtration and oil/water separation.

工业废气和含油废水的大量排放，严重危害生态环境和人体健康。对于研究人员来说，开发坚固的功能材料来控制空气污染和净化实际恶劣环境中的含油废水仍然是一个巨大的挑战。在此，通过连续静电纺丝策略成功制备了聚丙烯腈（PAN）@TiO ₂ /聚（偏二氟乙烯-共聚六氟丙烯）（PVDF-HFP）@SiO ₂纳米纤维（PTPS _{NF ）Janus膜。}由于其独特的双层结构和多组分的协同作用，复合过滤器克服了高过滤效率和低空气阻力的权衡效应，实现了99.7%的过滤效率（PM _0.327 Pa 的压降。吸湿性 PAN@TiO ₂层和自清洁 PVDF-HFP@SiO ₂层的结合使 Janus 过滤器在个人防护领域具有明显的优势。同时，PTPS _NF膜经过强酸/碱处理后仍保持优异的空气过滤性能。此外，由于其不对称的润湿性，PTPS _NF Janus 膜具有可切换的油/水分离能力，可以有效分离不同的油/水混合物和乳液，具有高通量和分离效率。因此，强大的功能性 Janus 纳米纤维过滤器在恶劣环境的空气过滤和油/水分离中提供了迷人的应用前景。