ZnO@TiO2/PDMS Superhydrophobic Antibacterial Coating with Photocatalytic Activity, Durability, and Self-Cleaning Properties

Superhydrophobic antibacterial coatings offer an effective approach to overcoming the limitations of single anti-adhesion or bactericidal strategies; however, it remains a great challenge to develop such coatings with long-term durability and high bactericidal performance. In this study, a ZT/PDMS composite coating was successfully fabricated by directly mixing ZnO@TiO2 with PDMS. Benefiting from the low surface energy of polydimethylsiloxane (PDMS) and the coral-like micro/nanostructured rough morphology generated by the incorporation of ZnO@TiO2 nanoparticles, the coating exhibited excellent superhydrophobic properties, with a water contact angle of 153.5°. The proposed fabrication method showed good adaptability to various substrates, and the resulting coating demonstrated outstanding durability and self-cleaning performance. Notably, the coating retained superhydrophobicity after six abrasion cycles, and the water contact angle remained above 140° after immersion in solutions with pH ranging from 1 to 13 for 7 days. The ZT/PDMS composite coating achieved an antibacterial adhesion rate of 87.98% and 80.11% against Acinetobacter baumannii (A. baumannii) and Staphylococcus aureus (S. aureus), respectively. Under UV and visible light irradiation, its bactericidal efficiency exceeded 90%. The excellent antibacterial performance of the coating was attributed to the synergistic effects of anti-adhesion, active sterilization (Zn2+ release and ROS generation), and self-cleaning. This study provides a facile and effective strategy for the development of efficient and durable multifunctional antibacterial coatings.