Fig. 6: Proton conductivity at various RH and temperatures.

a The Nyquist plots of 2 at 30 °C and various RH (60–98%). b Humidity-dependent proton conductivity of 1 and 2 at 30 °C. c The water vapor adsorption and desorption isotherms of 1 and 2 at 30 °C. d The Nyquist plots of 2 at 98% RH and various temperatures (30–80 °C). e Arrhenius plot of the proton conductivity of 1 and 2. f The ν(OH) region of water molecules obtained from in situ IR spectra of 1 and 2 under a water vapor pressure of 2.5 kPa (P/P0 = 0.90). The observed bands were reproduced by the sum of four Gaussian peaks. Source data are provided as a Source Data file.