Competitive adsorption of urea and Et4NBr at the electrode/electrolyte interface

The simultaneous adsorption of urea and tetraethylammonium bromide has been investigated in ternary solutions varying in composition from 10 −3 to 1 mol ℓ −l . The adsorption of urea at the electrode/electrolyte interface can be described at low surface coverage by a Langmuir isotherm taking into account the surface unoccupied by the ionic components of the Et 4 NBr salt. At high surface coverage, perturbation of Г urea by the simultaneous adsorption of the electrolyte is explained in terms of the lateral attractive forces previously observed in concentrated bulk solutions.