THE DOUBLE-LAYER AT THE INTERFACE BETWEEN A SIMPLE METAL AND AN AQUEOUS-SOLUTION

We consider the interface between a simple metal, modelled as jellium, and an aqueous solution. In order to estimate the effect of the water on the distribution of electrons in jellium, we perform molecular dyn amics simulations using the central force model for water. From these simulations, and from an effective pseudopotential for the electron-wa ter interaction, we obtain the average interaction potential experienc ed by the metal electrons. Explicit model calculations for a mercury e lectrode predict a significant lowering of the electronic work functio n in water. The position of the effective image plane is also brought closer to the jellium edge, which results in better values for the dou ble layer capacity.