ZIF-8@SiO₂ composite nanofiber membrane with bioinspired spider web-like structure for efficient air pollution control

Severe air pollution causing by particulate matter and VOCs calls for multifunctional air purification media. Here, we report a novel bioinspired bead-on-string-like ZIF-8@SiO₂ composite nanofiber membrane, which has a synergistic promoting effect on particulate matter (PM) capture and gas pollutants adsorption. The flexible SiO₂ nanofiber membrane was fabricated by electrospinning, while zeolitic imidazolate framework-8 (ZIF-8) nanocrystals were grown on the nanofibers by controlling the crystallization by contra-diffusion. The resultant ZIF-8@SiO₂ composite membrane showed high removal efficiency of 99.96% for incense smoke which attributed to the ZIF-8 enhanced surface area and electrostatic interaction between beaded ZIF-8 nanocrystals and PM particles. Further, the uniformly loaded ZIF-8 nanocrystals with compatible pore size, large microporosity and specific surface area enhanced the formaldehyde adsorption efficiency to 79.53% in 2 h. The design of the ZIF-8@SiO₂ composite membrane with fascinating PM removal efficiency and excellent formaldehyde adsorption capacity would make it a promising medium for multicomponent air purification.