Antimicrobial activity of printed composite TiO2/SiO2 and TiO2/SiO2/Au thin films under UVA-LED and natural solar radiation

Irina Levchuk*, Marcela Kralova, Juan José Rueda-Márquez, Javier Moreno-Andrés, Sergio Gutiérrez-Alfaro, Petr Dzik, Stephane Parola, Mika Sillanpää, Riku Vahala, Manuel A. Manzano

*Corresponding author for this work

Research output: Contribution to journalArticleScientificpeer-review

19 Citations (Scopus)

Abstract

Composite TiO2/SiO2 porous coatings modified with bipyramid-like gold nanoparticles were prepared by means of sol-gel and inkjet printing technique, comprehensively characterized and studied for photocatalytic disinfection of drinking water with fecal contamination by natural bacteria consortia. Photocatalytic antimicrobial activity of prepared thin films was evaluated against gram-negative (Escherichia coli and Total coliforms) and gram-positive bacteria (Enterococci). Elimination rate of all tested bacteria increased when photocatalytic coatings were used in comparison with solar disinfection. The best results in terms of antimicrobial activity were obtained with TiO2/SiO2/Au thin films under natural solar radiation, which demonstrated the highest antimicrobial activity, enhancing the inactivation rates of E. coli, Total coliforms and Enterococci 1.5, 1.3 and 1.6 times, respectively as compared to solar disinfection without photocatalyst. Remarkable difference in bacteria sensitivity for photocatalytic disinfection was observed with trend E. coli > Total coliforms > Enterococci. No release of gold and titanium was detected during photocatalytic water disinfection test. Regrowth of E. coli, Total coliforms and Enterococci after photocatalytic bacteria inactivation under UVA-LED and natural solar radiation was lower than 1% (24, 48 and 72 h), indicating potential application of prepared coatings for production of safe drinking water.

Original languageEnglish
Pages (from-to)609-618
Number of pages10
JournalAPPLIED CATALYSIS B-ENVIRONMENTAL
Volume239
DOIs
Publication statusPublished - 30 Dec 2018
MoE publication typeA1 Journal article-refereed

Keywords

  • Enterococci
  • Escherichia coli
  • Gold bipyramids
  • Total coliforms
  • Water disinfection

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