In light of the increasing contamination of the environment by hazardous chemicals, there is great interest to develop innovative technologies for the safe destruction of toxic pollutants. The processes must be cost-effective, easy to operate, and capable of achieving total or near total mineralization. This has prompted researchers to investigate innovative chemical oxidation technologies. Photocatalytic oxidative destruction of pollutants in wastewater provides the ultimate solution for the treatment of hazardous wastes. Photocatalysis would be a promising simple technique which can be used for both the degradation of organic pollutants and the removal of metals in onepot systems. The process requires ultra violet (UV) light which can be artificial or natural sources. Among the most promising compounds for photo catalysis applications is titanium dioxide. TiO2, as efficient and stable catalyst, is one of the least expensive semiconductors. However, the major impediment to its wide spread application, particularly indoor, resides in the fact that TiO2 absorbs near-UV light (Eg=3.2 eV for anatase). This band gap does not match very well with solar spectrum. Therefore, a visible-light activated catalyst is desired that can take advantage of a larger fraction of the solar spectrum and would be much more effective in environmental cleanup. Nanostructured (~20- 30 nm) particles provide the optimal balance between volumetric and surface recombination and are thus best suited for photocatalysis. The photoelectronic properties of TiO2 can be strongly influenced by the dopants that introduce new electronic energy levels inside the band gap. Substitutional doping of nitrogen in TiO2 has revealed an improvement in visible light photocatalytic activity.(

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