Preparation of TiO2 Nanorods Composites Doped with Silver Nanoparticles and Their Bactericidal Properties under Visible Light Irradiation

Abstract

TiO₂ is a widely used photocatalytic antibacterial material and shows good antibacterial properties under ultraviolet light. However, its antibacterial efficacy under visible light still remains limited. To develop low-cost and biocompatible antibacterial materials, this article provides a facile method for in situ preparation of a trace amount of silver (Ag) doped TiO₂ nanorods (TiO₂NR–Ag) composites, which cannot only enhance the antibacterial properties under visible light, but also has good biocompatibility. Two representative epidemic strains, Staphylococcus aureus and Escherichia coli, are selected for analysis of the antibacterial properties of the obtained TiO₂NR–Ag composite nanoparticles. The results demonstrate that even if the Ag doping level is as low as 2.5 × 10⁻⁴ wt% (i.e., Ag/TiO₂ = 2.50 µg g⁻¹), the TiO₂NR–Ag composite nanoparticle coatings are transparent and exhibit exceptional antibacterial properties, which is attributed to synergistic enhanced bactericidal effect of the active substances generated by TiO₂NR–Ag under visible light. The cytotoxicity and hemolysis rate results indicate that TiO₂NR–Ag composite exhibit excellent biocompatibility. This study effectively improves the antibacterial effect of TiO₂ photocatalytic nanomaterials while maintaining their biocompatibility, and the prepared TiO₂NR–Ag composite nanoparticles can be applied in various fields such as window glasses, medical device surfaces, furniture surfaces, and optical devices, etc.