P. Nikitas, A UNIFIED TREATMENT OF THE EQUILIBRIUM PROPERTIES OF ELECTROSORBED LAYERS COMPOSED OF NEUTRAL AND IONIC SPECIES, Electrochimica acta, 41(14), 1996, pp. 2159-2170
Classical thermodynamics is used in combination with the electrostatic
theory to develop generalized expressions for the electrochemical pot
entials of neutral and ionic species of multicomponent layers adsorbed
on electrode surfaces. The proposed approach allows all kinds of dipo
le-dipole, field-dipole, ion-field and ion-image interactions to be re
adily taken into account. The electrochemical potentials are used for
the derivation of the equilibrium equations, ie the adsorption isother
ms and the equation of state. A number of limiting cases of the multic
omponent adsorption are briefly examined. The attention is focused on
the effect of the specific adsorption of anions on the adsorption feat
ures of a neutral organic adsorbate. It is found that the theoretical
predictions are in general agreement with experiment. The most interes
ting of the predicted properties is the increase in the adsorption of
an organic adsorbate in the presence of adsorbed anions when the elect
rode charge density is used as the independent electrical variable. In
direct experimental evidences of this phenomenon are presented from li
terature and an explanation within the framework of our theory is give
n. Copyright (C) 1996 Elsevier Science Ltd