Photocatalytic Au-TiO2 nanocomposite synthesis and applications

Nanoparticle such as TiO2 nanoparticles (TiO2 NPs), have gained much attention due to their antibacterial activity, good photocatalytic performance, low cost, non-toxicity and environmentally friendliness. The antibacterial activity of TiO2 NPs mainly stems from the production of reactive oxygen species (ROS) upon illumination with UV light. However, the bandgap of TiO2 NPs (3.0-3.2 eV) is wide, which limits its visible light absorption. Herein, Au incorporated TiO2 nanocomposites with enhanced visible light absorption and transfer abilities were first synthesized through a hydrothermal method. Then, an Au-TiO2 nanocomposite incorporated sodium alginate film was prepared by a simple casting method. The film shows efficient visible light absorption ability and excellent antimicrobial properties against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) due to large ROS produced under visible light.