Photocatalytic Process: Schematic Illustration of a Typical System

This schematic illustrates the photocatalytic process in a typical photocatalytic system. The process begins with a semiconductor photocatalyst absorbing light energy, which excites electrons from the valence band to the conduction band, leaving behind holes in the valence band. The excited electrons can then reduce an electron acceptor, while the holes can oxidize an electron donor. This process can be used to drive various chemical reactions, such as the degradation of pollutants, the production of hydrogen, and the synthesis of organic compounds.