Controllable fabrication of nanosheet-inserted urchin-like MH@CoP Z-scheme heterojunction for enhanced physical and photocatalytic synergistic antibacterial performance

A novel nanosheet-inserted urchin-like MH@CoP Z-scheme heterojunction is prepared via hydrothermal and phosphorylation processes, for the antibacterial approach. The MH@CoP exhibits excellent broad-spectrum antibacterial activity, through synergizing the physical/mechanical piercing and the photocatalytic antimicrobial process, and the antibacterial efficiency against Staphylococcus aureus (S. aureus), Escherichia coli (E. coli) and Methicillin-resistant Staphylococcus aureus (MRSA) under visible-light irradiation are all over 90%. The nanosheet-inserted urchin-like structure of MH@CoP provides a unique Mg-Co heterojunction interface, favorable inducing the rapid separation and flow of photogenerated carriers through Z-type charge-carrier transfer, thus improving the charge separation efficiency. Consequently, this improvement facilitates the generation of massive reactive oxygen species (ROS) under visible-light excitation, that sterilize bacteria through oxidation. Besides, the outward-facing spikes of MH@CoP provide complementary mechanical piercing of bacterial cell membranes. The synergistic antibacterial mechanisms are confirmed that the MH@CoP, especial the positively charged magnesium hydroxide nanosheets in it, capture bacteria rapidly and the adsorbed bacteria are then in-situ eliminated through piercing and ROS oxidative damage under visible illumination. The excellent antibacterial performance plus the superior reusability and low cytotoxicity, make MH@CoP a good candidate for antimicrobial infection and implant disinfection.