Nanocrystal Cu2O-loaded TiO2 nanotube array films as high-performance visible-light bactericidal photocatalyst

Abstract

In this work, we report the use of a non-toxic nanocrystal Cu2O-loaded TiO2 nanotube array (Cu2O/ TNTs) film as high-performance visible-light bactericidal photocatalyst. The samples were characterized by fieldemission scanning electron microscopy, X-ray photoelectron spectroscopy, and ultraviolet–visible diffusion reflection spectroscopy. This Cu2O/TNTs film photocatalyst is capable of complete inactivation of Escherichia coli in 5× 107 colony-forming units/mL within a record short disinfection time of 20 min under visible-light irradiation. The average bactericidal percentage of the Cu2O/TNTs for E. coli under visible-light irradiation are 20 times and 6.6 times higher than those of TNTs under the same conditions and Cu2O/TNTs without light, respectively. This superior bactericidal performance is mainly attributed to the high ability to produce OH radicals by both photogenerated electron and hole of the prepared photocatalyst under visible light. The Cu2O/TNTs film photocatalyst makes it applicable to broad fields including drinking water disinfection.