Zeolite imidazole framework-8(ZIF-8) decorated keratin-based air filters with formaldehyde removal and photocatalytic disinfection performance

Air pollution, consisting of particles of broad sizes, bioaerosols, and gaseous toxic chemicals, has become a serious hazard to public health. However, conventional fibrous filters have the disadvantages of high air resistance and limited ability to remove toxic gaseous and inhibit harmful microorganisms. Herein, we report a bilayer multifunctional air filter material based on applying electrospinning and needle-punching methods to generate hierarchically structure. Specifically, the air filter consists of keratin-based nanofibers as an upper layer and ZIF-8-modified polyethylene terephthalate/polyethylene needle-punched materials as the substrate. Green, facile, and controllable sonication process involved in thermally-assisted coating method was used to incorporate ZIF-8 onto the substate. The exposed functional groups of keratin and porous ZIF-8 nanocrystals with a high surface area promote the capture capability for small particulate pollutants and toxic gaseous molecules. Meanwhile, the needle-punched substrate with large pores significantly reduces the pressure drop and imparts photocatalytic disinfection performance to the air filter by the excellent photocatalytic characteristic of ZIF-8. This study proposes a novel strategy to fabricate hierarchical multifunctional air filters by combining electrospinning and needle-punching and plays a guidance role in designing and developing keratin-based hybrid materials.