Copper sulfides (Cu7S4) nanowires with Ag anchored in N-doped carbon layers optimize interfacial charge transfer for rapid water sterilization.

Structural optimization promotes water sterilization by low-voltage pulsed electric field. [Display omitted] • Cu 7 S 4 nanowire coated with N -doped carbon film is beneficial to the anchoring of Ag, and the loaded silver particles enhance the adsorption of O 2. • The successful coating of N -doped carbon layer and Ag particles improved the poor durability and conductivity of Cu 7 S 4. • The work function and electron difference density of different kinds of N -doped Cu 7 S 4 @NC@Ag demonstrate the direction of interface carrier transport. • The removal efficiency can still reach 99% after 8 h of continuous treatment at 6 V and 1000 mL min−1 flow rate. There are many methods of water disinfection, and how to realize low energy consumption, high efficiency and safety sterilization has always been a research hotspot. In this work, Cu 7 S 4 nanowires were grown on copper foam, and coated with N -doped carbon layer and Ag particles, which not only improved the conductivity and local field enhancement regions of the material, but also improved the durability and mechanical stability of Cu 7 S 4. DFT (Density functional theory) calculation shows that different kinds of N doping make the electron difference density and work function of the surrounding C different, which leads to high carrier transport capacity at the interface, and Ag anchored in N -doped carbon films can adsorb O 2. The band gap of the material is 2.12 eV, and the material has the potential to generate superoxide anion under energy excitation. Under the condition of 6 V voltage and 1000 mL min−1 water flow rate, the long-term water filtration sterilization of high-concentration bacteria can be realized, and the removal efficiency can still reach 99% after 8 h continuous treatment. This work has great application prospects for the purification of highly polluted water in the future. [ABSTRACT FROM AUTHOR]