TiO2 catalyst is n-type semiconductor material. As long as the semiconductor absorbs photons of no less than the band gap width，it enters the excited state together with the formation of light-induced hole in the valence band simultaneously. It is perfectly capable of capturing electronic,and the photo-induced electron e- in the conduction band also has high activity to form a redox system in the semiconductor surface through which most of the organic pollutants and partial inorganic pollutants eventually degrade into innoxious substances. It describes the application of photocatalytic oxidation technology in the field such as treatment of industrial wastewater (inorganic polluted water; dye wastewater; papermaking wastewater; pesticide wastewater; oily wastewater) and drinking water. The research shows that various indexes (chromaticity; COD; mineralization rate; bacteria inactivation rate, etc.) of this technology in water treatment application have achieved the required standards.
A Comparison of Photocatalytic Oxidation Reactor Performance for Spacecraft Cabin Trace Contaminant Control Applications