A Comprehensive Review on the Structure and Visible-Light-Driven Antimicrobial Properties of WO₃/TiO₂/CuO Nanocomposites

The WO3/TiO2/CuO nanocomposites exhibit potent and broad- spectrum antimicrobial activity under visible light, primarily due to synergistic mechanism involving the generating of reactive oxygen species (ROS) and the release of Cu2+ ions. Under light exposure, the heterojunction structure promotes efficient interaction at the nanoscale, leading to the production of ROS such as hydroxyl radicals (•OH) and super oxide anions (•O2-). These reactive species damage microbial cell membranes, protein, and nucleic acids, inducing oxidation stress that ultimately result in microbial cell death. Additionally, the sustained release of Cu2+ ions enhances the antimicrobial efficacy by disrupting cellular processes and increasing membrane permeability. Simultaneously Cu2+ ions interact with microbial cells by disrupting membrane integrity, denaturing proteins and interfering with DNA replication and enzymatic pathways. This dual mode mechanism effectively inactivation both Gram -negative and Gram-positive bacterial (Eg: E.coli, S. aureus ) as well as fungal strains (Eg: Candida albicans, Aspergillus niger) demonstrating the nanocomposites potential as a powerful antimicrobial agent for diverse application, including disinfection, biofilm control and environmental purification.