Photocatalytic ozonation inactivation of bioaerosols by NiFeOOH nanosheets in situ grown on nickel foam

Inactivation of bioaerosols is critical to prevent the spread of microbial pathogens in air. Photocatalytic inactivation processes are environmental friendliness, while time-consuming and insufficient reactive oxygen species (ROSs) generation to irreversibly inactivate bacteria in bioaerosols. In this work, a novel photocatalytic ozonation (PCO) system was constructed, consisting of in situ grown NiFeOOH nanosheets on nickel foam (NiFeOOH NSs/NF) and trace concentration of ozone (O3). Specifically, the PCO system exhibited remarkable photocatalytic inactivation efficiency (99.99%) within an ultrashort retention time of 8.07 s (RH = 90%) while no bacteria survived after 24-h cultivation. The irreversible inactivation of bacteria in this PCO system attributes to the synergistic effect of physical destruction by NiFeOOH NSs/NF and oxidative damage by photogenerated ROSs. This research provides a better alternative for efficient inactivation of bioaerosols and opens the door for the application of PCO system in reducing the exposure risk of bioaerosols. [Display omitted] •NiFeOOH nanosheets were in situ grown on Ni foam surface by one-step redox method.•The photocatalytic ozonation system of NiFeOOH nanosheets/Ni foam/O3 was constructed.•The inactivation efficiency is 99.99% and rises with increase of RH and retention time.•The high efficiency is attributed to synergy of oxidative damage and physical destruction.•This system causes the irreversible death of bacteria in bioaerosols.