Bacterial Inactivation on Concrete Plates Loaded with Modified TiO₂ Photocatalysts under Visible Light Irradiation

Area of Science:

• Materials Science
• Environmental Science
• Microbiology

Background:

• Antibacterial materials are crucial for public health and infection control.
• Photocatalytic materials offer a promising approach for disinfection.
• Developing effective antibacterial concrete could reduce pathogen transmission in built environments.

Purpose of the Study:

• To investigate the antibacterial efficacy of concrete plates embedded with various titania photocatalysts.
• To identify specific photocatalyst compositions that confer significant antibacterial properties to concrete.
• To evaluate the performance of these materials against Escherichia coli under simulated solar irradiation.

Main Methods:

• Concrete plates were loaded with different titania photocatalysts at a 10 wt.% concentration.
• Antibacterial activity was tested against Escherichia coli K12.
• Bacterial inactivation was assessed under artificial solar light irradiation.
• The modified Hom disinfection kinetic model was applied to analyze the inactivation data.

Main Results:

• Concrete plates with specific nitrogen- and carbon-doped titania photocatalysts demonstrated significant antibacterial activity.
• Total inactivation of Escherichia coli was achieved with TiO2/N,CMeOH-300, TiO2/NCEtOH-100, TiO2/NisoPrOH-100, and TiO2/N-300 loaded concrete.
• The study identified photocatalyst structure (nitrogen and carbon content), crystallite size, surface area, and porosity as key factors influencing antibacterial properties.

Conclusions:

• The incorporation of specific titania photocatalysts significantly enhances the antibacterial properties of concrete.
• These photocatalytic concrete materials are effective in inactivating Escherichia coli under artificial solar light.
• Material characteristics such as nitrogen/carbon doping and physical properties are critical for optimizing antibacterial performance.