Understanding bactericidal performance on ambient light activated TiO2–InVO4 nanostructured films

Abstract

TiO₂–InVO₄ nanostructured films were coated onto glass substrates and systematically investigated for their bactericidal activities using Escherichia coli (E. coli) as the model bacterium under ambient light illumination. The uniform TiO₂–InVO₄ nanostructured films were prepared using titanium isopropoxide (TTIP) as the precursor via a simple sol–gel approach. Polyethylenimine (PEI) was used as a surfactant to ensure uniform dispersion of InVO₄ and a sacrificial pore-inducing agent, generating nanostructured films. Compared to unmodified TiO₂ film, the current TiO₂–InVO₄ films exhibited enhanced bactericidal activities under ambient light illumination. Bacterial cell “photo-fixation” was demonstrated to be crucial in enhancing the bactericidal activity. A bacterial–nanostructured surface interaction mechanism was proposed for the current ambient-light activated nanostructured film.