N-doped carbon-coated Cu2O nanowire arrays on copper foam for rapid and stable water disinfection.

ABSTRACT

High-speed, low-cost and long-term water disinfection method is important for us to away from waterborne diseases. Nanowires-modified electrodes can inactivate microorganisms under low energy consumption. However, small processing capacity remains a major obstacle for practical application. In this study, we coated N-doped carbon layer on Cu2O NWs to improve the conductivity and stability for electrodes. Compared with Cu2O, the work functions of Cu2O-PANI structures is 3.623 eV, indicating the electrodes can prevent the recombination of electron-hole pairs and improve the carrier transport efficiency. In addition, Mulliken charge density showed that Cu2O-PANI structure reduce the oxidation trend of Cu atom and improve the stability of electrodes. Besides, the Cu2O NWs@NC electrodes showed excellent disinfection performance for E. coli and S. aureus, which can achieve 99.9% sterilizing rate under high flux (1200 mL min-1). Under this condition, the electrodes can continuously treat 576 L wastewater, which is about 10-folds handling capacity than others. Moreover, the bactericidal mechanism is synergistic of electroporation and reactive oxygen species, and the main ROS were electrons, OH and O2-. Therefore, this electrodes has a great prospect for rapid and stable water treatment system.