Phosphors-Based Photocatalysts for Wastewater Treatment
Every day a large amount of products has been released by chemical and pharmaceutical industries threatening the environment and human health. Moreover, their removal using conventional oxidation methods is difficult because a lot of pollutants are biorecalcitrant. Photocatalysis, an advanced oxidation technology, appears one of the most viable solutions due to its ability to oxidize a wide range of toxic organic compounds into harmless compounds such as CO2 and H2O by irradiation with UV light. Organic pollutants can be removed from water by a UV-driven photocatalytic process involving nanoparticles with semiconducting properties. However, their use in a photoreaction system suffers of the disadvantage due to the no-uniform photon distribution inside the reactor core.
The chapter describes a possible solution for enhancing the photon distribution inside the photoreactors, using inorganic and organic light-emitting particles (phosphors) coupled with photocatalysts to be applied in water and wastewater treatment. The chapter also underlines the difference between inorganic particles having down-conversion, up-conversion, and long-afterglow luminescence properties. Additionally, the use of up-conversion organic phosphors has been proposed. Finally, some examples concerning the use of semiconductors coupled with different photoluminescent materials in the removal of pollutants from water and wastewater are presented.
KeywordsPhotocatalysis Wastewater treatment Phosphors Down-conversion phosphors Up-conversion phosphors Long-afterglow phosphors Organic up-conversion phosphors Coupling with photocatalysts Doped photocatalysts UV and visible light
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