Manganese dioxide-filled hierarchical porous nanofiber membrane for indoor air cleaning at room temperature

Indoor air pollution, including atmospheric particular matter 2.5 (PM2.5) and chemical gaseous pollutants (HCHO), has been an ongoing concern. Seeking a practical strategy for protection of the indoor air quality (IAQ) remains a challenge. Herein, we demonstrated a hierarchical porous membrane consisting of the birnessite-type MnO₂ that was filled in the polystyrene porous nanofibers (MnO₂/PS HPNM) fabricated by a versatile electrospinning method. The effective air cleaning of both PM2.5 and HCHO at remarkably low resistance was achieved by dominating the hierarchical porous structure. The HCHO gas could easily permeate through the mesopores of the PS nanofibers and contact MnO₂, thereby resulting in an excellent HCHO removal efficiency of 88.2% after the initial run and 74% after five cycles. In addition, the pore-filling MnO₂ with the layered structure increased the nanofiber membrane surface area, thus enhancing its PM capture performance (99.77%). Moreover, the macropores from the interwoven nanofibers ensured clean air penetration leading to a low airflow resistance of 82 Pa. The hierarchical multifunction porous structure membrane provided a new approach for the IAQ protection.