Visible-Light-Active CuOx-Loaded Mo-BiVO₄Photocatalyst for Inactivation of Harmful Bacteria (Escherichia coliandStaphylococcus aureus) and Degradation of Orange II Dye

In the present study, Mo-BiVO₄-loaded and metal oxide (MO: Ag₂O_x, CoO_x, and CuO_x)-loaded Mo-BiVO₄photocatalysts were synthesized using a wet impregnation method and applied for microbial inactivation (Escherichia coliandStaphylococcus aureus) and orange II dye degradation under visible-light (VL) conditions (λ ≥ 420 nm). The amount of MO cocatalysts loaded onto the surface of the Mo-BiVO₄photocatalysts was effectively controlled by varying their weight percentages (i.e., 1-3 wt %). Among the pure Mo-BiVO₄, Ag₂O_x-, CoO_x-, and CuO_x-loaded Mo-BiVO₄photocatalysts used in bacterialE. coliandS. aureusinactivation under VL irradiation, the 2 wt % CuO_x-loaded Mo-BiVO₄photocatalyst showed the highest degradation efficiency ofE. coli(97%) andS. aureus(99%). Additionally, the maximum orange II dye degradation efficiency (80.2%) was achieved over the CuO_x(2 wt %)-loaded Mo-BiVO₄photocatalysts after 5 h of radiation. The bacterial inactivation results also suggested that the CuOx-loaded Mo-BiVO₄nanostructure has significantly improved antimicrobial ability as compared to CuO_x/BiVO₄. The enhancement of the inactivation performance of CuOx-loaded Mo-BiVO₄can be attributed to the synergistic effect of Mo doping and Cu²⁺ions in CuO_x, which further acted as an electron trap on the surface of Mo-BiVO₄and promoted fast transfer and separation of the photoelectron (e^-)/hole (h⁺) pairs for growth of reactive oxygen species (ROS). Furthermore, during the bacterial inactivation process, the ROS can disrupt the plasma membrane and destroy metabolic pathways, leading to bacterial cell death. Therefore, we provide a novel idea for visible-light-activated photocatalytic antibacterial approach for future disinfection applications.