The unique electronic band structure of TiO2 makes it as a stand-alone photocatalyst, and an ideal choice for the photocatalysis. TiO2 adsorbs photons with sufficient energy (λ< 380 nm or UVA) and results in generation of electrons (e-) - hole (h+) pairs. These conduction band electrons and valence band holes on the surface can react with surface bound O2 or H2O to initiate redox reactions so as to generate reactive oxygen species (ROS) like hydroxide radicals (OH-), superoxide radicals (O2-) and hydrogen peroxide (H2O2) in various chain reactions. The photo generated reactive oxygen species on the TiO2 coated surfaces can able to avoid surface cross-contamination by effectively killing pathogenic microorganisms as shown below.