Hybrid Cu₂O/TiO₂ Nanocomposites with Enhanced Photocatalytic Antibacterial Activity toward Acinetobacter Baumannii

The hybrid Cu₂O-TiO₂ photocatalytic composite with a p-n heterojunction was synthesized by the supercritical solvothermal route. The uniformly distributed Cu₂O was stably combined with TiO₂ to benefit the increase of the specific surface area, the harvesting of visible light, and the separation of photogenerated holes and electrons. As a result, photocatalytic inactivation of Acinetobacter baumannii under visible-light irradiation was facilitated. Based on the photogenerated holes acting as the main active species, the Cu₂O-TiO₂ photocatalytic heterojunction could induce the leakage of K⁺ ions and serious damage of the cell structure, leading to the final cell death. During the photoantibacterial process on Cu₂O-TiO₂, the RecA gene played a significant role in enhancing the survival rate of Acinetobacter baumannii. Furthermore, the great bactericidal effect of Cu₂O-TiO₂ nanocomposites to different bacteria indicated the potential application for the environment-friendly disinfection.