Hydration Energy-Dependent Ion Intercalation on Graphite and the Asymmetric Electrowetting.

Ion intercalation in graphite is widely used in desalination, batteries, and graphene stripping; it has high value in the fields of industry and research. However, selective ion transport, particularly (de)hydration energy and the hydration shell effect on the intercalation of ions into the graphite interlayer spaces, is still unclear. Here, we report low-voltage ion intercalation as observed by electrowetting on highly oriented pyrolytic graphite of an aqueous drop containing various inorganic salts.