Multifunctional self-cleaning bactericidal Cu2O/TiO2 coating with durable superhydrophobicity and visible-light photocatalytic activity

Antimicrobial coatings with self-cleaning and long-lasting antibacterial properties are critical for medical applications to reduce healthcare-associated infections. However, existing coatings pose challenges of poor durability, limited light response, or rapid antibacterial agent loss. Herein, we report a scalable strategy to fabricate a Cu 2 O/TiO 2 composite coating (CT-37, Cu:Ti = 3:7 mass ratio) via in-situ chemical reduction and two-step semi-curing spraying, integrating hierarchical micro-nanostructured Cu₂O/TiO₂ particles with lithium polysilicate adhesive. CT-37 exhibits good superhydrophobicity (contact angle ( θ CA ) = 151.3 ± 1.4°, roll-off angle ( θ RA ) =3.4 ± 0.4°), retaining a θ CA  > 150° after 10 abrasion cycles and 7 days of acid/alkali immersion. Under visible light, it achieves >99% sterilization efficiency against Escherichia coli and Staphylococcus aureus , and maintains a > 90% bactericidal rate after 50 cycles. This study reveals a novel synergistic mechanism: (i) superhydrophobicity reduces bacterial adhesion by minimizing solid-liquid contact area; (ii) rapid Cu ion release from the coating matrix directly inhibits bacterial proliferation; (iii) photocatalytic generation of reactive oxygen species (ROS, including •O 2 − , h + , and •OH) under visible light further eradicates adhered microbes. This cost-effective coating, coupled with the deepening understanding of its antimicrobial mechanism, paves the way for large-scale medical and public health applications.