CuWO4 doped with Se for enhanced photocatalytic antibacterial activity

Abstract

This study successfully synthesized selenium-doped CuWO₄ photocatalysts via a hydrothermal method and systematically investigated their visible-light-driven antibacterial performance and mechanistic pathways. Experimental results reveal that selenium doping concentration significantly modulates the photocatalytic activity, with the optimal doping level of 0.7 mmol achieving remarkable antibacterial efficiency. Under 100 min of visible-light irradiation, the material achieved 99.9% inactivation of S. aureus at an initial concentration of 10⁷ CFU mL⁻¹. Systematic characterizations, including radical trapping experiments, scanning electron microscopy (SEM), and intracellular genetic material leakage assays, demonstrate that selenium doping introduces electron-trapping centers, effectively suppressing charge carrier recombination. This optimization enhanced the photocatalytic antibacterial activity by 2.3 times compared to pristine CuWO₄ and significantly promoted the generation of reactive oxygen species (ROS: ˙OH, ˙O₂⁻, and ¹O₂). The resultant ROS disrupt bacterial cell wall integrity via lipid bilayer destruction, induce membrane permeability alterations, and provoke cytoplasmic leakage, collectively leading to efficient bacterial inactivation. This work elucidates the atomic-level mechanism of selenium-enhanced photocatalytic activity in tungstate-based materials and provides fundamental insights for designing advanced semiconductor photocatalysts for antimicrobial applications.