Inorganic Photoelectrochemistry from Illumination Techniques to Energy Applications

Abstract

This chapter takes a glance at the evolutionary course of photoelectrochemistry. It is assumed that the reader is well familiarized with the alphabet of electrochemistry and the principles of thermodynamics and kinetics in classical electrochemistry. All the contents of this chapter, about the pure and applied photoelectrochemistry and their applications in different fields, have been designed proportional to the requirements and limitations of a concise handbook. The references at the end of the chapter provide the avid reader with the resources for more in-depth information. The first part of the chapter is dedicated to the history of photoelectrochemistry and the most important discoveries that laid the foundation for the innovative methods and applications in the recent years. This is followed by an introduction to the semiconductors and the electron energy levels and energy band model. In the third section, essential photoelectrochemical measurements have been outlined. Subsequently, the conditions for the presence of electrons in a solution and the main differences between a metal and a semiconductor are explained. Sections 9.4, 9.5, 9.6, 9.7, 9.8, and 9.10 cover equilibrium and the electrode-electrolyte interface, the traditional theories and calculation of the photocurrent (in the dark or under illumination), absolute electrode potential, and semiconductor electrodes. The following sections discuss practical applications of semiconductors and photoelectrochemistry by using the work of top researchers in photoelectrocatalysis, photoelectrochemical reduction of CO2, photoelectrolysis of H2S, water photosplitting, and waste treatment by photoelectrochemistry. In the last part of the chapter, the photoelectrochemical devices are briefly discussed.