Cu-Doped TiO2: Visible Light Assisted Photocatalytic Antimicrobial Activity

Snehamol Mathew, Priyanka Ganguly, Stephen Rhatigan, Vignesh Kumaravel, Ciara Byrne, Steven J. Hinder, John Bartlett, Michael Nolan, Suresh C. Pillai

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33 Citations (Scopus)

Abstract

Surface contamination by microbes is a major public health concern. A damp environment is one of potential sources for microbe proliferation. Smart photocatalytic coatings on building surfaces using semiconductors like titania (TiO2) can effectively curb this growing threat. Metal-doped titania in anatase phase has been proven as a promising candidate for energy and environmental applications. In this present work, the antimicrobial efficacy of copper (Cu)-doped TiO2 (Cu-TiO2) was evaluated against Escherichia coli (Gram-negative) and Staphylococcus aureus (Gram-positive) under visible light irradiation. Doping of a minute fraction of Cu (0.5 mol %) in TiO2 was carried out via sol-gel technique. Cu-TiO2 further calcined at various temperatures (in the range of 500–700 °C) to evaluate the thermal stability of TiO2 anatase phase. The physico-chemical properties of the samples were characterized through X-ray diffraction (XRD), Raman spectroscopy, X-ray photo-electron spectroscopy (XPS) and UV–visible spectroscopy techniques. XRD results revealed that the anatase phase of TiO2 was maintained well, up to 650 °C, by the Cu dopant. UV–vis results suggested that the visible light absorption property of Cu-TiO2 was enhanced and the band gap is reduced to 2.8 eV. Density functional theory (DFT) studies emphasize the introduction of Cu+ and Cu2+ ions by replacing Ti4+ ions in the TiO2 lattice, creating oxygen vacancies. These further promoted the photocatalytic efficiency. A significantly high bacterial inactivation (99.9999%) was attained in 30 min of visible light irradiation by Cu-TiO2
Original languageEnglish
JournalApplied Sciences
Volume8
DOIs
Publication statusPublished - 26 Oct 2018

Keywords

  • Cu-doped TiO2
  • doping
  • phase transition
  • Escherichia coli
  • Staphylococcus aureus
  • photocatalysis
  • antibacterial coatings

Cite this

Mathew, S., Ganguly, P., Rhatigan, S., Kumaravel, V., Byrne, C., Hinder, S. J., Bartlett, J., Nolan, M., & Pillai, S. C. (2018). Cu-Doped TiO2: Visible Light Assisted Photocatalytic Antimicrobial Activity. Applied Sciences, 8. https://doi.org/10.3390/app8112067