Role of Electric Field and Reactive Oxygen Species in Enhancing Antibacterial Activity: A Case Study of 3D Cu Foam Electrode with Branched CuO–ZnO NWs

Water is critical to public health. An inexpensive, fast, and effective water treatment has the potential to significantly impact human life. In this work, we reported a novel device for highly effective water disinfection. Branched CuO–ZnO nanowires (NWs) on a foam copper substrate were prepared, which possessed excellent antibacterial performance and good stability. The nanostructured assembly achieved a large electric field concentration and improved production of reactive oxygen species (ROS) to inactivate bacteria at low voltages through electroporation and oxidative stress. The nanostructure materials showed high antibacterial activity against Escherichia coli and Staphylococcus aureus at a high concentration (106 CFU mL–1) under an external voltage of less than 10 V and a hydraulic retention time of less than 2 s. Moreover, the application of electric field favored the production of ROS. The structure containing branched CuO–ZnO NWs possessed a better disinfection ability than that with CuO NWs.