Moreover, depositing some Ag NPs on the surface of TiO2 NPs increases their antiviral efficiency against MS2 by means of increased production of hydroxyl radicals.196 A Ag- and Cu-doped TiO2 nanowire membrane is more active in eliminating bacteriophage MS2 from drinking water than are TiO2, Ag-TiO2, or Cu-TiO2 membranes, both in the dark and when exposed to UV light.