Figure 3: Surface charge-governed proton transport through vermiculite channels.
From: Self-assembled two-dimensional nanofluidic proton channels with high thermal stability

(a) Schematic illustration and (b) photo of the vermiculite nanofluidic device. (c) Representative I–V curves through the 2D channels. (d) Ionic conductivity as a function of electrolyte concentration. The deviation from bulk solution at low proton concentration is characteristic of surface charge-governed transport.