Photoelectrochemical refers to a process that involves the interaction between light and chemical reactions. It is based on the photoelectric effect, where electrical current is generated by exposing certain materials to light. In this process, photons of light interact with electrons in a material, causing them to be emitted or released from the surface. This results in an electric current flowing through the material and can initiate chemical reactions that are dependent on the presence of light energy. Photoelectrochemical processes have many applications, including solar energy conversion, photocatalysis, and sensors for detecting specific substances.