This study investigated the role of Cu as a doping agent to enhance photocatalytic activity of TiO2 in
Cu-doped TiO2/glass fibers (Cu-TiO2/GF) used for disinfection of Escherichia coli (E. coli) in aerosols under
visible light irradiation. Glass fiber was used as a substrate to immobilize TiO2 for disinfection of E. coli
in bioaerosols. Cu in the prepared photocatalyst acted as an intermediate agent for the transfer of photogenerated
electrons from the valence band to the conduction band of TiO2. Cu dopants increased the
electron-hole pair separation efficiency, inhibited their recombination leading to a lifetime increase of
the generated electrons, and thus improved photocatalytic activity even under visible light irradiation.
Cu also defected the TiO2 lattice by producing Ti3+ ions, which can increase the electron-hole separation
capacity of the photocatalyst, thereby increasing photocatalytic capacity. The optimal Cu content
in Cu/TiO2 to enhance the photocatalytic activity of TiO2 was 5 wt.%. Among three humidity conditions
(dry (40
±
5%), moderate (60
±
5%) and humid (80
±
5%)), the moderate condition showed the highest
disinfection efficiency of E. coli. When the 5% Cu-TiO2/GF was used under a moderate level of humidity,
the highest disinfection efficiency and disinfection capacity of E. coli were identified as 87.8% and 23
CFU/s cm2, respectively.