Fabrication of Cu₂O-Ag nanocomposites with enhanced durability and bactericidal activity

Hybrid Cuprous oxide-silver (Cu₂O-Ag) have attracted tremendous attention due to their various applications in photocatalysis, surface enhanced Raman scattering (SERS), and optical features. Here we expanded the application to exhibit excellent chemical stability and synergistic bactericidal. We prepared Cu₂O-Ag heterostructure through thermally decomposing Ag-acetate to deposit Ag nanoparticles (Ag NPs) onto Cu₂O surface. Cu₂O-Ag heterostructure bears exceptional stability while exposing to oxygen, water, and light, owing to the physical coating of Ag NPs and transferring the electrons and holes inside the Cu₂O to the surface through a Schottky barrier to prevent photocorrosion. The deposition of Ag NPs also improved the intensity and time of oxidative stress reaction of Cu₂O, proved by reactive oxygen species (ROS) examination. Ag NPs distributed on the surface of Cu₂O particles formed a large of ion release channel, resulting in excellent sustained release of copper ions. Density functional theory (DFT) calculations were used to investigate the mechanism of photocatalysis and ROS generation. The constructed Cu₂O-Ag heterostructure exhibit highly long-term sterilization activity against Staphylococcus aureus (S. aureus) and Pseudomonas aeruginosa (P. aeruginosa) which were maintained around 70% and 80% and were increased by 40% and 50% compared with free Cu₂O after being immersed in phosphate buffer saline (PBS) solutions within 14 days.