Self-Doped Cu-Deposited Titania Nanotubes as Efficient Visible Light Photocatalyst

Poor crystallinity and applications restricted to only UV region of titanate nanotubes (TNTs) generated numerous routes towards high surface area visible photocatalysts. In this study, TNTs were prepared via alkaline hydrothermal synthesis route followed by deposition of visible light sensitive CuO on their surface via photoreduction method under anoxic conditions. Photodeposited Cu(II) oxide was confirmed by means of EPR and DR-UV-Vis spectroscopy. Further annealing in 5% H-2/N-2 gas mixture introduced oxygen vacancies associated with Ti3+ defect sites, which additionally enhanced photocatalytic activity under visible light. Using such photocatalyst, almost complete inactivation of bacteria Escherichia coli was achieved within 60 min of illumination with visible light.