Fig. 5: In-situ Raman characterizations and AIMD simulations of the electrode/electrolyte with three typical organic cations (TMA, TPA, DHDMA).
From: Steric and hydrophilic/hydrophobic effects of organic cations on electrochemical CO reduction
a Comparison of Raman spectra at −0.8 V. b–d Heatmaps of ν(*CO) stretching vibration under different potentials. 100% iR compensation was applied, and the solution resistance (R) was 18 Ω for TMA, 22 Ω for TPA, and 70 Ω for DHDMA. e Ratio of the ν(O-H)/ν(C-H) band area under different potentials. The gray-shaded region denotes the potential range for CORR performance testing. f Raman spectra of ν(Cu-OH) and ν(O-H) with peak deconvolution at −0.8 V. g Ratio of strongly hydrogen-bonded water (sh-H2O) under different potentials. h AIMD structural optimization of Cu(111)/water interface with different organic cations. The O, H, N, C, and Cu atoms are represented by red, gray, cyan, black, and golden colors, respectively. Hydrogen bonds are colored in dark blue, while those formed by the -OH group of DHDMA are highlighted in orange. i Phonon density of states (DOS) of -OH vibration in the AIMD simulations with different cations. The marker over the curve represents the central value of the corresponding signal. Source data for (a–g, i) are provided as Source data files.
