Efficient Air Disinfection Achieved by Nanowire-Modified Copper Mesh Electrodes

Airborne pathogens can widely spread and cause severe diseases in humans, concerning the risks of indoor exposure in hospitals, homes, and malls. Therefore, the inactivation of pathogens in indoor air environments is important. The inactivation of microorganisms in water by nanowire electroporation has been well studied in recent years. But the effectiveness of nanowire-modified electrodes for air disinfection is still unknown. In this study, a disinfection method for the quick inactivation of bacteria in air is reported. The copper meshes were modified with Cu(OH)2 nanowires by electrochemical method. A flow-through device with nanowire-modified electrodes inside was designed to generate, mix, and disinfect bioaerosols. 60-85% inactivation efficiency for bacteria and more than 2-log removal for viruses were achieved with a short air retention time of 0.3 s in high humidity (RH of 100%). Endospores showed a susceptibility to electric disinfection similar to that of the vegetable cells. The inactivation efficiency of bacteria in moderate humidity (RH of 40%) could be significantly improved up to 51% by coating with a high conductive material, poly(3,4-ethylenedioxythiophene):poly(styrene-4-sulfonate) (PEDOT:PSS). The main inactivation mechanism in air was demonstrated as electroporation by detecting membrane integrity. This novel disinfection method may be applied for the disinfection of air-transmitted pathogens in the future.