Achieving High Carrier Mobility of Fe-ZnO and Cu-ZnO Laminated Homo-junction Nanofilm for Rapid and Highly Effective Photocatalytic Sterilization

The transmission of pathogenic bacteria via the contaminated surfaces of interactive touchscreens is an important route of infection. It is therefore imperative to develop a functional film with antibacterial properties to prevent cross-infection. In this paper, a bilayer thin-film structure composed of iron-doped and copper-doped zinc oxide (Fe-ZnO/Cu-ZnO) is synthesized through a spin coating technique based on sol-gel. The synergistic effects of metal ion doping, combined with the influence of the internal electric potential, during the photocatalytic reaction process, promote the separation and migration of photogenerated carriers. As a result, it notably boosts the photocatalytic properties. The nanofilm is demonstrated to achieve a rapid bactericidal effect (surpassing 90%) under sunlight irradiation. Furthermore, it is shown to completely kill bacteria after 20 min of illumination and to maintain excellent antibacterial performance (surpassing 90%) for a period of 30 days. Concurrently, the thin film displays both exceptional light transmittance (surpassing 90%) and noteworthy benefits, including environmental sustainability, cost-effectiveness, and the capacity for safe disinfection. The thin film exhibits considerable potential for implementation on surfaces subject to high-frequency public contact. It boasts extensive application prospects and serves as a foundational reference for the design of photocatalytic antibacterial thin films.