Photocatalytic Antimicrobial Treatments

Photocatalytic antimicrobial textiles incorporate semiconductor photocatalysts (TiO₂, ZnO, g-C₃N₄) that generate reactive oxygen species (•OH, O₂•⁻, H₂O₂) upon light activation to kill microorganisms without releasing soluble biocides. TiO₂ (anatase, bandgap 3.2 eV) activated by UV (>3.0 eV, λ<387 nm) achieves 4–6 log bacterial reduction in 30–120 min (ISO 20743 adapted method). Visible-light-active systems via N-doping, Ag deposition, or graphene composites extend activity to 400–700 nm solar spectrum. Applied at 1–5 g/m² via sol-gel, hydrothermal, or padding methods. Self-regenerating biocidal activity upon light re-exposure differentiates photocatalytic systems from all conventional leaching or contact-kill antimicrobials.