Titanium dioxide (TiO2), an example of metal-oxide type semiconductors, has been studied and widely used as a photocatalytic material for self-cleaning coatings, environmental purifiers, antifogging mirrors and many other applications [1]. TiO2 has a bandgap of 3.0 eV for the rutile phase and 3.2 eV for the anatase phase. These values require ultraviolet (UV) radiation to activate