chapter  2
64 Pages

Principles of Electrochemistry

WithHeinz Gerischer

Electrochemistry covers all phenomena in which a chemical change is the result of electric forces and, vice versa, where an electric force is generated by chemical processes. It includes the properties and behavior of electrolytic conductors in liquid or solid form. Electrochemical experiments are performed in electrolysis cells which consist of two electrodes in contact with an electrolyte. Electrolytes have a definite voltage range of stability in a galvanic cell before they are decomposed by electrolysis in which one component is oxidized, the other reduced, provided the electrodes themselves remain inert in this voltage range. Semiconductors have a much lower concentration of mobile electronic charge carriers than metals, and their accumulation at the contact to an electrolyte can, therefore, not be treated like a surface charge. Charge transfer reactions at interfaces are strongly affected by the electric forces which are present in the electric double layer. Electrochemical deposition of semiconductors has been achieved in only a very few cases.