Nanostructured TiO₂ anatase-rutile-carbon solid coating with visible light antimicrobial activity

Area of Science:

• Materials Science
• Nanotechnology
• Photocatalysis

Background:

• Titanium dioxide (TiO2) is explored for antimicrobial coatings on hospital surfaces.
• Enhancing TiO2 photocatalytic activity under visible light is a key research area.

Purpose of the Study:

• To develop and characterize a nanostructured TiO2 coating with enhanced visible light photocatalytic activity.
• To investigate the potential of this coating for antimicrobial applications.

Main Methods:

• Pulsed-pressure Metal-Organic Chemical Vapor Deposition (pp-MOCVD) was used to deposit thick TiO2 coatings on stainless steel.
• The microstructure, including anatase, rutile, and amorphous carbon composite, was analyzed.
• Antimicrobial efficacy against E. coli under visible light was tested.

Main Results:

• A unique mille-feuilles nanostructure of anatase and dendritic rutile with amorphous carbon was formed.
• The nanostructured coating exhibited an effective surface area ~100 times greater than standard TiO2.
• A >3-log reduction in viable E. coli was achieved after 4 hours of visible light exposure.

Conclusions:

• The pp-MOCVD method enables scalable production of nanostructured TiO2 coatings with superior photocatalytic and antimicrobial properties.
• This approach avoids nanoparticle synthesis, offering a practical manufacturing route for functional materials.