Adsorption at charged interfaces plays an important role across all aspects of physical chemistry, from biological interactions within living organisms to chemical processes such as catalysis and separations. With recent advances in materials chemistry, there are a host of modified electrodes being investigated for electrosorption, especially in separations science. In this perspective, we provide an overview of functional interfaces being used for electrosorption, ranging from electrochemical separations such as deionization and selective product recovery to biological applications. We cover the various molecular mechanisms which can be used to enhance ion capacity, and in some cases, provide selectivity; as well as discuss the parasitic Faradaic reactions which often impair electrosorption performance. Finally, we point to the importance of electrochemical configurations, in particular the advantages of asymmetric cell design, and highlight the opportunities for selective electrosorption brought about by redox-mediated systems.