Cold Spraying for Titanium Dioxide Coatings with High Photocatalytic Bactericidal Activity

Titanium dioxide in anatase phase structure has high antibacterial activity. For this study, titanium dioxide coatings on stainless steel were produced by cold spraying. The bactericidal effect of the coatings was tested with Pseudomonas aeruginosa bacteria at a high concentration of more than 107 CFU (colony-forming units) per milliliter. The bacteria were applied on the surface and exposed to UV light with a peak intensity of 360 nm. A kill rate of 99,99% was already achieved after 5 minutes, while the raw stainless steel reference did not show any significant reduction even after 60 min. The results show that cold-sprayed titanium dioxide coatings can serve as self-disinfecting surfaces.