High-Efficiency and Stable Cathode Disinfection in Real Water Systems via Convenient In Situ Prepared Copper-Cuprous Oxide Nanowires

As global pollution intensifies, water contamination─a critical issue for both human and ecological survival─has become increasingly severe. Consequently, there is an urgent need for a rapid and stable water disinfection method to ensure clean water. In this study, high-surface-area Cu composite films were first deposited on a conductive substrate through an in situ electrodeposition process. The derived copper nanowire (M-Cu/Cu₂O NWs) electrodes were then synthesized by controlled in situ growth and electrochemical reduction-decomposition of the Cu composite films. The working electrode was then placed on the cathode for water disinfection. The results demonstrated excellent and stable antimicrobial performance against <i>Escherichia coli</i>, <i>Staphylococcus aureus</i>, and <i>Citrobacter freundii</i>. The in situ reduction method for preparing derived copper electrodes can help prevent reoxidation during synthesis, promote the formation of an excellent crystal structure, and reduce grain boundaries and defects, thereby enhancing the mechanical strength and chemical stability of the Cu/Cu₂O nanowires. Furthermore, the cathodic environment of the working electrode significantly reduces metal corrosion caused by oxidation, further enhancing its durability. The sterilization mechanism is the membrane's electroporation caused by nanowires' tip effect. It has been demonstrated that the M-Cu/Cu₂O NWs cathode electrode can continuously maintain a bacterial inactivation rate above 90% for 30 days at an 8 V working potential. Due to the simple electrode fabrication method, stable disinfection efficiency, and significant reduction in copper ion release, which minimizes secondary environmental contamination, this system holds great potential for safe and stable water treatment applications.