Spontaneous formation of irregular honeycomb-structured nanobowls/nanofibers bimodal bulk filter for cooking fumes purification using combined electrospraying and electrospinning.

Waste emissions, including cooking fumes (CFs) generated from anthropogenic activities, significantly contribute to respiratory diseases. Nanofiber-based filters are ideal materials for high-efficiency air filtration. Nevertheless, the fabrication of bulk filters for the efficient removal of multiple components remains a challenge. Herein, we present an effective strategy for the spontaneous formation of a three-dimensional (3D) irregular honeycomb-structured bimodal bulk filter (BBF) composed of nanobowls and nanofibers through simultaneous electrospraying and electrospinning. The BBF, incorporating recycled polyester (rPET) nanofibers and β-cyclodextrin (β-CD) nanobowls, demonstrates exceptionally low air resistance (30.08 pa) and a high oily aerosol removal efficiency of 94.01 %. It features a fluffy configuration with substantial porosity (94.85 %) and minimal packing density (0.23 g cm-3). Notably, this BBF achieves purification efficiencies of 95.27 %, 88.74 %, and 89.37 % for particulate matter, non-methane hydrocarbons, and volatile organic compounds, respectively, indicating its effective integrated properties for multiple components. This superior filtration performance is enabled by the synergistic effects of a large filtration area and enhanced turbulent capture. Furthermore, the BBF exhibits outstanding reusability for filtering actual CFs. This work advances our understanding of the spontaneous formation process of specific 3D stacking structures composed of particles and nanofibers, providing an innovative strategy for the development of BBFs.