Surface photodynamic ion sterilization of ITO-Cu2O/ZnO preventing touch infection

Abstract

• An ITO-Cu 2 O/ZnO heterojunction was constructed on ITO conductive glass by electrodeposition and atomic layer deposition. • The photocatalytic ability of ITO-Cu 2 O/ZnO was enhanced due to the formation of p-n junction. • The ITO-Cu 2 O/ZnO exhibited efficiently bacteria-killing under solar light irradiation for 3 min. • The coating of ZnO had a protective effect on the water corrosion of Cu 2 O and prolonged the service life of the hybrid film. Pathogenic microbial infections are threatening the people's health and even life. The most common channel of infections can be caused by skin contact, especially hand touching facilities such as touching screen. In this work, Cu 2 O covered with ZnO nanofilm was prepared on the surface of indium tin oxide conductive glass by electrodeposition and the followed atomic layer deposition process. This composite coating had a light transmittance of 71.5%, which met the light transmission needs of touch screen device. Electron spin resonance spectra showed that composite materials can generate more reactive oxygen species (ROS) than a single component under solar light irradiation. This was because a p-n junction with a built-in electric field was formed at the interface after Cu 2 O contacting with ZnO. In the process of photocatalysis, photogenerated electrons and holes migrated at the interface driven by the built-in electric field, which promoted the separation of carriers. The antibacterial rate against Staphylococcus aureus reached 92.5% after 3 min of light irradiation with simulated sunlight due to the synergy of ROS and Cu ions, Zn ions. Therefore, this work may provide a potential method for antibacterial application of preventing hand touch infections.