Arming nanofibers with MnO₂ nanosheets for fast and durable removal of ozone and particulate matter from air

Indoor air pollution, including particulate matter (PM) and ozone (O₃), is a significant threat to public health. Membrane separation is considered to be an effective strategy to control air pollutants. However, the development of multifunctional membrane for efficiently eliminating PM and O₃ remains challenging. Herein, upon a simple one-step hydrothermal reaction, Cl-doped MnO₂ nanosheets were assembled onto electrospun nanofibrous membranes to achieve effective air purification of PM and O₃ with low resistance. The MnO₂ composed of layered ultrathin nanosheets increased the particle attachment points, and enriched the pore structure and roughness of nanofibers, thereby achieving excellent filtration efficiency of PM_0.3 (>95 %) and maintaining low pressure drop (40 Pa). In addition, the introduction of Cl element in PI/MnO₂ (PI/MnO₂–Cl) nanofibrous membranes created a large specific surface area, high redox property, and abundant water-resistant oxygen vacancy (Ov), which accelerated the desorption of intermediates and reduced the water adsorption during O₃ conversion. Notably, the optimized catalytic membranes exhibited a stable O₃ decomposition efficiency of 94.5 % under a relative humidity (RH) of 90 %. This work provides a potential new strategy to fabricate modified MnO₂-based dual-function nanofibrous membranes for PM trapping and O₃ decomposition with sustained low airflow resistance.