Potential of monolayer charge

In this letter, we develop the concept of the potential of monolayer charge (PMC). Its main purpose is to serve as the fundamental reference potential for studying charged interfaces. We estimate PMC values for interfaces between Au(111) surface and frisbee-shaped ions. Density functional theory calculations suggest that increasing ion area shifts the PMC to an experimentally measurable potential range. To guide experimental verification, we have derived an analytical expression, which relates ion area, surface–ion distance, ionic charge, and the corresponding PMC value. Further exploration of the PMC can enrich interfacial electrochemistry and reveal interfacial electrophysics as an independent field.