Structure of the metal aqueous electrolyte solution interface

Theoretical results are given for aqueous electrolyte solutions in contact with uncharged metallic surfaces. The metal is modeled as a jellium slab and is treated using local density functional theory. The solution structure is obtained using the reference hypernetted-chain theory. The two phases interact electrostatically and the coupled theories are iterated to obtain fully self-consistent results for the electron density of the metal and surface-particle correlation functions. The metal-induced structure of pure water and aqueous electrolyte solutions as well as the electrostatic potential drop across the interface are discussed in detail. The results are compared with those for ions in simple dipolar solvents. It is found that the water molecules are ordered by the metal field and that the surface-induced solvent structure strongly influences the ion distributions. (C) 1997 American Institute of Physics.