Thermally oxidized PAN as photocatalyst support layer for VOCs removal

Photocatalytic filter plays a key role in VOCs removal and ensuring the long-term durability of photocatalytic filter is essential for increasing their lifespan in real-world industrial application. However, how to unlock the stability of organic supporting materials as photocatalytic filter has not been taken into account. In this work, photocatalyst TiO₂ nanoparticles were successfully immobilized on a polyacrylonitrile (PAN) nonwoven using a solvent swelling method, followed by a thermal oxidation treatment. The photocatalytic efficiency of prepared PAN nonwovens in VOCs removal was investigated and the effect of surface treatments and thermal oxidation process on fibers photostability and thermal characteristics were explored. The obtained thermal-oxidized TiO₂@PAN nonwoven showed photocatalytic efficiencies of 75% and 92% for the degradation of toluene and formaldehyde gases, respectively, under simulated sunlight. Compared with the TiO₂@PAN nonwoven, the photo-induced degradation rate of oxidized-TiO₂@PAN nonwoven decreased by 43%, and TGA-DTG results demonstrated a superior thermal stability of the oxidized PAN sample. The findings of this research can facilitate the application of novel PAN-based nonwoven filters in photocatalytic removal of VOCs by providing higher efficiency, improved thermal stability and photostability.