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

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, Cu7S4 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 Cu7S4. 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 O2. 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.