Confined electrochemistry in nanocavities: Perspective and techniques

The understanding that chemical reactions carried out under nanoconfinement behave significantly differently than in the bulk has motivated electrochemists to study electrochemical processes in nanometer-sized volumes. Significant work has been performed in nanopores where the reactants and products enter and leave at different places. This has been primarily applied to protein and DNA sequencing. Yet, fewer studies have been devoted to studying electrochemical reactions in nanocavities where there is only a single opening. This review summarizes the growing activity in this relatively new area, which includes the approaches for making nanocavities, the ways the nanocavities are analyzed, and the present and future applications. Well-defined nanocavities enable studying a variety of charge transfer processes under nanoconfinement conditions.