Among the various nanocrystalline photocatalytic materials
that have been studied over the last 30 years, research has mainly
focused on titanium dioxide (titania, TiO2) as photocatalyst in
diverse areas ranging from water and air treatment to self
cleaning surfaces. In the past yearsTiO2 has beenmodified to suit
various applications.WO3/TiO2 has been successfully tested for
selective catalytic reduction (SCR) of NOx in lean exhaust gases