Antibacterial Performance of a Gold-Loaded g-C3 N4 Nanocomposite System in Visible Light-Dark Dual Mode

Dimensional-matched two dimensional/two dimensional TiO2/Bi2O3 step-scheme heterojunction for boosted photocatalytic performance of sterilization and water splitting

A Step-scheme (S-scheme) heterojunction can regulate the directional migration of powerful photogenerated carriers and realize high photocatalytic activity. Herein, we propose a novel dimensional matched S-scheme photocatalyst comprising of two-dimensional (2D) TiO₂ nanosheets and 2D Bi₂O₃ nanosheets for environmental and energy applications, such as water sterilization and water splitting. X-ray photoelectron spectroscopy (XPS), electron paramagnetic resonance, in-situ irradiated XPS and theoretical calculations provided strong evidence that the photocarrier migration in the TiO₂/Bi₂O₃ composite followed the S-scheme mode, which efficiently prevented the recombination of powerful photocarriers, thereby enabling the heterojunction with a strong redox ability for producing abundant reactive oxygen species. The tight and large 2D/2D interface minimized the distance of photocarrier migration to further extend the lifetime of useful photocarriers (active radicals for sterilization and photoelectrons for H₂ generation). The 2D/2D TiO₂/Bi₂O₃ heterojunction demonstrated an improved photocatalytic antibacterial performance with complete inactivation of 4.63 × 10⁷ CFU mL^-1Escherichia coli cells within 6 h in water. In addition, the heterojunction displayed a H₂ generation rate of 12.08 mmol h^-1g^-1 through water splitting process. This study provides a potential bifunctional photocatalyst for minimizing the adverse impact of pollution on the environment.

Recent advances in graphite carbon nitride-based nanocomposites: structure, antibacterial properties and synergies

Bacterial infections and transmission threaten human health and well-being. Graphite carbon nitride (g-C₃N₄), a promising photocatalytic antibacterial nanomaterial, has attracted increasing attention to combat bacterial transmission, due to the outstanding stability, high efficiency and environmental sustainability of this material. However, the antibacterial efficiency of g-C₃N₄ is affected by several factors, including its specific surface area, rapid electron/hole recombination processes and optical absorption properties. To improve the efficiency of the antibacterial properties of g-C₃N₄ and extend its range of applications, various nanocomposites have been prepared and evaluated. In this review, the advances in amplifying the photocatalytic antibacterial efficiency of g-C₃N₄-based nanocomposites is discussed, including different topologies, noble metal decoration, non-noble metal doping and heterojunction construction. The enhancement mechanisms and synergistic effects in g-C₃N₄-based nanocomposites are highlighted. The remaining challenges and future perspectives of antibacterial g-C₃N₄-based nanocomposites are also discussed.