Metal-organic framework decorated polyimide nanofiber aerogels for efficient high-temperature particulate matter removal

Particulate matter (PM) originated from high temperature (200–300 °C) does great harm to public health, could be effectively removed via high-temperature air filters. Nevertheless, a mass of obstacles still remain in the way of exploiting a high-temperature air filter with simultaneously high mechanical strength, excellent air filtration performance and good thermal stability. Herein, we report a robust and efficient nanofiber aerogel-based air filter fabricated by compounding zeolite imidazole framework-8 (ZIF-8) nanoparticles with polyimide (PI) nanofiber aerogels. As the matrix material, the robust and porous PI nanofiber aerogel endows the filter with satisfactory air permeability, outstanding adsorption capacity, great thermal stability and favorable mechanical performance. Moreover, the dispersed ZIF-8 provides a good deal of active sites, which is beneficial to capture finer PMs by electrostatic attraction. As a result, ZIF-8/PI composite nanofiber aerogel (ZIF-8/PI NFA) exhibits great high-temperature filtration performance. At 300 °C, ZIF-8/PI NFA is able to remove 96.2 % and 99.5 % of PM0.3 and PM2.5 with slight pressure drop of 88.5 Pa (air face velocity of 5.3 cm s−1), and it can continuously work under 300 °C without any performance attenuation. This ZIF-8/PI NFA with high efficiency, good thermal stability and great mechanical properties displays a broad application prospect in industrial and automotive air purification fields.