Enhanced catalytic ozonation inactivation of bioaerosols by MnO2/Ni foam with abundant oxygen vacancies and O3 at atmospheric concentration

Abstract

Catalytic ozonation is a promising bioaerosol control technology, as O3 is prevalent in atmosphere. However, O3 at atmosphere concentration has limited oxidation potential and reactive oxygen species (ROSs) production, leading incomplete bioaerosol inactivation. Therefore, a catalytic ozonation system with a manganese dioxide/Ni foam (MN) was prepared for efficient bioaerosol inactivation. The MN exhibited superior activity in catalytic ozonation bioaerosol inactivation, achieving 91.6% inactivation efficiency within 8.07 s at atmospheric concentration (0.1 ppm) of O3. The inactivation efficiency can be further improved to 99.0% by regulating surface oxygen vacancies (OV) in MN, which is mainly attributed to abundant OV of MN that facilitate rapid conversion of O3 to other ROSs. Meanwhile, the mechanism of rapid bacterial inactivation was also clarified at cellular level, showing that ROSs caused bacterial oxidative stress. This catalytic ozonation strategy would offer more choices to design efficient O3 catalysts for bioaerosol control and public health protection.