ABSTRACT
Photocatalysis deals with exposing a semiconductor to sunlight or any other source of light during a reaction, but semiconductor sensitivity to that specic light or radiation is the necessary condition. Therefore, in order to make a semiconductor sensitive toward a major portion of sunlight (visible light), some chemical substance consisting of chromophores such as synthetic dyes, colored semiconductors, or natural pigments could be used. Chromophores are responsible for photosensory processes or may help in generating articial photoreactive systems as well.
