Titanium Dioxide nanoparticles in a water suspension?
https://www.researchgate.net/profile/Howard_Foster/publication/51080259_Photocatalytic_disinfection_using_titanium_dioxide_Spectrum_and_mechanism_of_antimicrobial_activity/links/53d664400cf220632f3d9e2c/Photocatalytic-disinfection-using-titanium-dioxide-Spectrum-and-mechanism-of-antimicrobial-activity.pdf
Interesting. Nice catch i think you are on to something. Thanks for posting that.