6533b86ffe1ef96bd12ce7f6
RESEARCH PRODUCT
Surface charges at the CaF2/water interface allow very fast intermolecular vibrational-energy transfer
Mischa BonnZhen ZhangDominika LesnickiMarialore SulpiziEllen H. G. BackusEllen H. G. Backussubject
540 Chemistry and allied sciencesMaterials science530 Physics2D sum-frequency generation010402 general chemistry01 natural sciencesCatalysisVibrational energy relaxationSurface chargeDiffusion (business)DissolutionResearch Articlesenergy transfer010405 organic chemistryIntermolecular forceGeneral ChemistryInterfacial Chemistryab-initio molecular dynamics530 Physik0104 chemical sciencesDipoleSolvation shellChemical physicsMolecular vibration540 Chemiesolid/liquid interfacesResearch Articledescription
Abstract We investigate the dynamics of water in contact with solid calcium fluoride, where at low pH, localized charges can develop upon fluorite dissolution. We use 2D surface‐specific vibrational spectroscopy to quantify the heterogeneity of the interfacial water (D2O) molecules and provide information about the sub‐picosecond vibrational‐energy‐relaxation dynamics at the buried solid/liquid interface. We find that strongly H‐bonded OD groups, with a vibrational frequency below 2500 cm−1, display very rapid spectral diffusion and vibrational relaxation; for weakly H‐bonded OD groups, above 2500 cm−1, the dynamics slows down substantially. Atomistic simulations based on electronic‐structure theory reveal the molecular origin of energy transport through the local H‐bond network. We conclude that strongly oriented H‐bonded water molecules in the adsorbed layer, whose orientation is pinned by the localized charge defects, can exchange vibrational energy very rapidly due to the strong collective dipole, compensating for a partially missing solvation shell.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2020-07-27 |