A general model to describe the electrostatic potential at electrolyte oxide interfaces

Colloid chemists have proposed several theories to describe the charging mechanism of metal oxides in electrolyte solutions and the resulting electrical double layer at the oxide surface. In this paper a new general theory to describe the electrostatic potential at the metal oxide electrolyte solution interface is presented. This theory describes the variations of the electrostatic potential as a function of the differential double layer capacitance and the intrinsic buffer capacity. ISFET measurements are interpreted using this theory, and it is shown that these measurements can differentiate between the theories for the double layer and the theories for the charging mechanism for the oxide.