Fig. 2: In situ NH4+ formation at the catalyst surface.
From: In situ ammonium formation mediates efficient hydrogen production from natural seawater splitting
a In situ SEIRAS spectra of different metal nitrides at −0.05 V in Ar-saturated natural seawater. b The proportion of NH4+ species in the EDL versus N 2p band center for different metal nitrides. c The proportion of s-HB-H2O versus the proportion of NH4+ species in the EDL for different metal nitrides. d Online electrochemical DEMS measurements over Mo2N catalyst in natural seawater. e The proportion of NH4+ species in the EDL of the Mo2N catalysts as a function of applied potentials. The proportion of NH4+ in the EDL were extracted from the in situ SEIRAS spectra in Supplementary Fig. 23. f Schematic of the NH4+ formation on the Mo2N surface. g Chronopotentiometry curves of Mo operated at −10 mA cm−2 in natural seawater with different concentration of NH4Cl and NaCl, respectively. The pH of the bulk seawater was fixed at 7.84 by adding NaOH. h The proportion of s-HB-H2O versus the proportion of NH4+ species in the EDL for the Mo catalyst operated at −0.05 V in Ar-saturated natural seawater with different concentrations of NH4Cl. The proportion of s-HB-H2O and the proportion of NH4+ were extracted from the in situ SEIRAS spectra in Supplementary Fig. 24.
