In 1985, Matsunaga and colleagues observed the antimicrobial
activity of TiO2 . In particular ,microbial cells could be killed by
the contact with a TiO2– Pt catalyst under illumination with near
UV light.When TiO2 is irradiated with photons of energy equal to
or higher than it sband-gap (3.15 eV for anatase,3.05 eV for rutile
crystalline phase ), electron – hole pairs are generated