Disinfection of Staphylococcus aureus in indoor aerosols using Cu–TiO2 deposited on glass fiber under visible light irradiation

Abstract

Abstract This study investigated the disinfection efficiencies of TiO 2 and Cu-doped TiO 2 photocatalysts, supported on glass fibers (GFs) under ultraviolet (UV) and visible irradiation, against Staphylococcus aureus ( S. aureus ) contained in an indoor aerosol. GFs were used as a substrate to immobilize TiO 2 and Cu-doped TiO 2 in order to expand the potential applications of these photocatalysts for air purification. The synthesized TiO 2 immobilized on GF (TiO 2 /GF) and Cu-doped TiO 2 immobilized on GF (Cu–TiO 2 /GF) photocatalysts were characterized using scanning electron microscopy (SEM) for morphology, X-ray photoelectron spectroscopy (XPS) for elemental states and ultraviolet–visible spectroscopy (UV–vis) for optical absorption properties. Under UV irradiation, the photocatalytic disinfection of S. aureus by Cu–TiO 2 /GF (94.54%) was higher than that by TiO 2 /GF (93.24%). Under visible light, TiO 2 /GF did not show any significant photocatalytic disinfection efficiency (3.27%), whereas Cu–TiO 2 /GF showed a high photocatalytic disinfection efficiency for S. aureus (over 67%), even under visible light, which was attributed to the effect of the Cu doping in increasing the electron–hole pair separation efficiency and electron–hole pair generation capacity of TiO 2 . Therefore, even under visible light, the Cu–TiO 2 /GF photocatalyst system could generate electron–hole pairs, which then reacted with water and oxygen molecules to produce oxy radicals, which are the main decomposing agents to disinfect or inactivate S. aureus in aerosols.