MXene‐Mediated Internal Electric Field in WO₃/AgBr Nanocomposites Enhances Visible‐Light‐Driven Peroxymonosulfate‐Activation and Dual‐Mode Antibacterial Performance

Designing heterojunctions that enable efficient charge separation without compromising redox potential is key to advancing visible‐light‐active photocatalysts for water treatment via advanced oxidation processes (AOPs). In this study, a rationally engineered WO 3 /AgBr/Ti 3 C 2 T x MXene ternary composite is synthesized and comprehensively evaluated for photocatalytic and antibacterial efficacy. Electron paramagnetic resonance and radical scavenging analyses confirmed the light‐induced generation of reactive oxygen species (ROS) such as • OH and O 2 •− . Supported by X‐ray photoelectron spectroscopy and density functional theory, an “indirect S‐scheme” charge transfer mechanism is proposed, where MXene facilitates selective recombination of low‐energy carriers while conserving high‐energy electrons and holes for efficient ROS production. The optimized composite exhibited a six‐fold improvement in photocatalytic activity over pristine WO 3 , which further doubled with peroxymonosulfate (PMS), achieving a twelve‐fold enhancement overall. Antibacterial studies under dark and light conditions reveal potent dual‐mode disinfection, with effective inactivation of Escherichia coli and Staphylococcus aureus . Agarose gel electrophoresis confirmed substantial DNA degradation in PMS‐assisted conditions, minimizing the risk of bacterial resuscitation. This multifunctional material, combining efficient charge dynamics, visible‐light responsiveness, and strong biocidal action, holds significant promise for integrated pollutant degradation and microbial disinfection in next‐generation AOP frameworks.