Silver nanoparticle coupled Cu2O/Ag/Bi2MoO6 Z-scheme heterojunction with enhanced visible light photocatalytic activity for bacteriostasis

Abstract

The construction of heterojunction has been considered as an effective strategy to achieve charge separation and improve photocatalytic activity. In this work, stable reduced Cu2O/Ag/Bi2MoO6 (Cu2O/Ag/BMO) nanocomposites with high-efficiency antibacterial activities were synthesized via a simple wet chemical method. After illumination of 30 days, Cu2O/Ag/BMO still showed excellent antimicrobial capability against P. aeruginosa and S. aureus. The photoluminescence spectroscopy was used to analyze the electrons and holes recombination efficiency of samples, which suggested Cu2O/Ag/BMO could promote electron-hole separation and extend the lifetime of photogenerated carriers. The results of photocurrent responses test suggested that the photocurrent density of Cu2O/Ag/BMO was four times stronger than the Cu2O, which indicated the higher separation efficiency of electrons and holes pairs for the formed Cu2O/Ag/BMO. Besides, density functional theory proved that Ag nanoparticles could promote the electrons transfer from the Bi2MoO6 layer to the Cu2O layer which facilitated the separation of photogenerated electron-hole pairs. Therefore, electrons and holes could better participate in the redox reactions and then generate more active substances (•OH and •O2–), improving the antimicrobial ability. Therefore, the prepared Cu2O/Ag/BMO composites has a great application prospect in the antifouling field.