Anodized multi – component titanium alloys carrying antibacterial features

Abstract

TiO2 nanotubes (NTs) obtained from multicomponent alloys by electrochemical anodization are prospective nanomaterials in photocatalytic reactions as well as in disinfection processes. New nanotubular structures were obtained in the anodization process from three – component alloys consisting of metals characterized by antibacterial properties and improved charge transfer. TiO2/Ag2O/Cu2O, TiO2/Ag2O/PtOX and TiO2/Ag2O/Au0 heterojunctions were obtained for the first time. The physicochemical properties of NTs layers were characterized by XRD, DRS, UV–vis, SEM, TEM, XPS and EDX. Antimicrobial properties were investigated in three model reactions – under visible irradiation (λ > 420 nm), in the dark and without photocatalysts in the presence of E.coli, S.aureus, Pseudomonas aeruginosa, K.oxytoca and Clostridium sp. Enhanced activity under visible irradiation was observed. The most efficient process of bacteria inactivation was obtained by TiO2/Ag2O/Au0 NTs. TEM images of bacteria after the process were prepared. The Mechanism of bacteria inactivation was studied. It is assumed that during the process the transfer of photoexcited electron from Ag2O to TiO2 emerged. Photogenerated electrons and holes get across with other substances to create reactive oxygen species including ̇O2, which led to damage of the bacteria cells.