Photoelectrochemistry and Applications

Abstract

In this section, we will be concerned with applications of photoelectrochemical cells (PEC). The term “photoelectrochemical” refers to any situation wherein light is used to augment an electrochemical process; the prefix photo implies in particular radiation of some kind, typically visible light of a continuous frequency range (e.g., solar) or of a single frequency. A photoelectrochemical cell involves photosensitive interphases, at least one of those, formed typically among solids and liquids – generally between electronic and ionic conductors. The radiation absorbed at these junctions stimulates physical and chemical actions, which may be exploited for construction of useful devices. The electrochemical schemes to be described concern mainly PEC applications of inorganic semiconductors in classical (macro) electrode cells. In these cells, semiconductor/liquid junctions are utilized much in the same way as semiconductor solid-state contacts, the essential difference being the nature of the active junction (solid–solid vs. solid–liquid).