Electrostatic Potentials at Solid/Liquid Interfaces*

This review deals with electrostatic potentials within solid/electrolyte interfaces. The electrostatic potentials of several planes are defined and discussed: the inner surface potential affecting the state of charged surface species due to interactions with potential determining ions (Ψ0), the potential affecting the state of associated counterions (Ψβ), the potential at the onset of diffuse layer (Ψd) and the electrokinetic potential (ζ). The relevance of zero values of these potentials is also discussed and the corresponding points of zero charge are defined. Experimental methods for the measurement of the interfacial potentials are presented. The relations between potentials and surface charges are given on the basis of the Surface Complexation model. Some experimental findings are provided.