Fe-doped ZnO nanoarrays towards high efficiency of non-contact electroporation disinfection in water

Low-voltage electroporation offers a sustainable and energy-efficient approach for water disinfection. However, this technique faces significant challenges, including inefficient charge transport and inadequate stability of nanoarray-modified electrodes, which undermine both disinfection performance and system stability. In this study, we overcame these challenges by introducing iron-doped zinc oxide nanoarrays (Fe-ZnO NAs) and integrating them into a novel Non-contact Electrode System (NES). The Fe-ZnO NAs exhibited an enhanced conductivity due to the iron doping, which greatly improved their electroporation disinfection performance. At a low voltage of 1 V and a short contact time of 0.6 s, 3 wt% iron-doped ZnO nanoarrays (Fe3-ZnO NAs) electrodes achieved remarkable bacterial removal efficiencies of 6.20-log for Escherichia coli ( E. coli ) and 1.69-log for Staphylococcus aureus ( S. aureus ), compared with only 1.94-log and less than 0.10-log, respectively, for the undoped ZnO NAs electrodes. Furthermore, the Fe3-ZnO NAs electrodes demonstrated excellent operational stability, maintaining over 6.00-log removal efficiency for E. coli during 30 min of continuous operation. These results establish the transformative potential of Fe-ZnO NAs as a high-performance, low-energy electrode material, offering a practical and efficient solution for water disinfection in real-world applications.