A phenomenological theory of electrosorption

A phenomenological theory of electrosorption is presented based upon notions of local charge and local electronic polarisability (Friedel oscillations). The strong link between the extent and nature of ionic and molecular adsorption at an electrode surface and the uv-absorption properties displayed by such molecular entities in an aqueous solution is emphasised. The theory may be used to predict, in certain cases the extent of ionic adsorption at the potential of zero charge (PZC) and, also, to rationalise recent results pertaining to metal underpotential deposition (UPD) processes on single crystal electrodes.