An effective air disinfection approach is necessary to prevent the spread of airborne microbial pathogens to protect public safety. Ozone is considered as a broad-spectrum and economical disinfection agent worldwide, while the health risks of ozone limited the practical application. In this study, we designed a flow-through O3-catalyst reactor disinfecting air by converting O3 into reactive oxygen species (ROS). FeOOH supported on TiO2 (Fe/TiO2) was prepared as a catalyst and the optimized O3-Fe/TiO2 reactor exhibits remarkable disinfection efficiency with a logarithmic (log) order of 3.53 (-log10 (C/C0)), which is 22-fold as high as that of ozone alone (8.2 ppm ozone and 93% relative humidity). Moreover, the O3-Fe/TiO2 reactor also exhibited significant disinfection efficiency (99.5%) and good stability (80 hours) with an ozone outlet concentration below 0.03 ppm which is the standard value recommended by World Health Organization air quality guidelines. The radical scavenging tests, electron paramagnetic resonance (EPR), and in situ Raman studies indicated the hydroxyl radical (•OH) dominated the catalytic ozonation disinfection. Furthermore, physicochemical characterizations, EPR, and electrochemical measurements revealed that the well-dispersed FeOOH increases the density of surface hydroxyl groups from 0.9 mM•g-1 to 1.5 mM•g-1 and accelerates the electron transfer between ozone and catalyst, which greatly improves the production of •OH and promotes the irreversible inactivation of bacteria. This catalytic ozonation reactor designed paves a promising way of efficient bioaerosols disinfection in open space and workplace with human beings to protect public health and achieve continuous production.
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