Fig. 2: Wien effect in interfacial water dissociation.
From: Wien effect in interfacial water dissociation through proton-permeable graphene electrodes
a Fermi energy μe at zero-current conditions as a function of pH. Dotted curve, guide to the eye. The arrows show the inferred electric field E using the analysis from c for the corresponding data points. b Proton conductivity, GH, of graphene devices measured simultaneously with μe in a (green symbols). Dotted curve, guide to the eye. Grey data points were obtained from few-layer graphene devices. The shaded area indicates typical conductivity caused by leakage. c GH(n) relation from a and b (top x-axis and y-axis), where n is the carrier density. Bottom x-axis, E = ne/ε0εr with dielectric constant εr = 6. Solid curve, best fit of Onsager model to data. Dotted curves, Onsager model for different εr. Small symbols in all panels: data points from individual measurements. Large symbols in all panels, average from small symbols for fixed pH. Error bars, SD.
