Air pollution is currently a huge threat to human health, which leads to heavy demand for efficient air filters. Herein, this work reports a facile and scalable strategy to fabricate a multilevel structure PA66@BN air filter to remove fine particles by combination solution blow spinning (SBS) and spraying. In this study, the composite membrane contains three structural features at multiscale: 1D polyamide 66 (PA66), 2D large surface area boron nitride nanosheets (BN), and 3D interconnecting network structure fiber membranes. The filtration efficiency of the composite membrane for PM2.5 and PM10 is >95%, the pressure drop is only 53 Pa, and the removal rate of 0.3 mu m ultrafine particles also can reach 90%, which realizes the characteristics of high efficiency and low resistance of high-quality filter. The presence of large transverse size BN increases the specific surface area and roughness of the nanofibers, reduces the probability of particle reflection and escape, and enhances the mechanical interception effect of the nanofibers on PM, while preserving the complex porous structure of 3D interconnection. Therefore, this study provides an economical and low-energy consumption new strategy for fabricating air filters with special forms to cope with the increasingly serious air pollution.
