Résumé
Graphene is completely impermeable in the perpendicular direction to its basal plane to all gases—even for helium, the smallest—at ambient conditions. In this context, it was expected that graphene would be impermeable even to protons, nuclei of hydrogen atoms. Nevertheless, we demonstrated that the transport of thermal protons through defect-free graphene is fast and can be measured experimentally. Graphene is also an excellent in-plane electron conductor. These properties allow using it as a proton permeable electrode. This talk will outline our work investigating its proton permeability and impermeability to all other ions, including recent work in which we demonstrate that defects are not necessary for its proton permeability. The talk will then cover the use of graphene as a proton permeable electrode to study proton transport, including the observation of a giant sensitivity to light. Using this well characterised system, we then explore the interfacial dissociation reaction (H2O = H+ + OH-) and discuss the observation of the Wien effect in this reaction in dark conditions and under illumination.
