Photocatalysis Essay

1018 Words3 Pages

Photocatalysis

Photocatalysis is a rapidly developing field of research with a high potential for a wide range of industrial applications, which include mineralization of organic pollutants, disinfection of water and air, production of renewable fuels and organic syntheses.
The word “photocatalysis” is of Greek origin and composes of two parts : the prefix “photo” (phos : light) and the word “catalysis” (katalyo : break apart,decompose). The main difference between a conventional thermal catalyst and a photocatalyst is that the former is activated by heat whereas the latter is activated by photons of appropriate energy.
Photocatalysis refers to the oxidation and reduction reactions on semiconductor surfaces, mediated by the valence band holes and conduction band electrons, which are generated by the absorption of ultraviolet or visible light radiation. Pairs of photo-generated hole (h+) and electron (e-) induce the formation of aggressive species such as hydroxyl or superoxide radicals from the moisture and atmospheric oxygen. These species are strong enough to oxidize and decompose organic materials or smelling gas and kill bacteria (see Fig 1). Several metal
The hydroxyl radical is the most important reactive species responsible for the destruction of the organic pollutant.

1.2.1.2. Sonolytic

Open Document