Photochemical properties, titanium dioxide pigments

Transparent titanium dioxide can be manufactured by various wet-chemical and gas-phase processes. The properties of the reaction products can vary greatly, depending on the reaction conditions and starting materials. To reduce the high photochemical activity of untreated transparent titanium dioxides, the pigments are coated with a variety of inorganic oxide combinations (e.g. of silicon, aluminum and zirconium oxides) [5.195]. 

---