Kosmotropic Electrolyte (Na2CO3, NaF) Perturbs the Air/Water Interface through Anion Hydration Shell without Forming a Well-Defined Electric Double Layer

Autor:	Jahur A. Mondal, Subhadip Roy
Rok vydání:	2021
Předmět:	Kosmotropic Sum-frequency generation Materials science Electrolyte Surfaces Coatings and Films Ion Chemical kinetics symbols.namesake Solvation shell Chemical physics Materials Chemistry symbols Physical and Theoretical Chemistry Spectroscopy Raman spectroscopy
Zdroj:	The Journal of Physical Chemistry B. 125:3977-3985
ISSN:	1520-5207 1520-6106
DOI:	10.1021/acs.jpcb.0c11024
Popis:	The ion-driven electric double layer (EDL) and the structural transformation of interfacial water are implicated in unusual reaction kinetics at the air/water interface. By combining heterodyne-detected vibrational sum frequency generation (HD-VSFG) with differential spectroscopy involving simultaneous curve fitting (DS-SCF) analysis, we retrieve electrolyte (Na2CO3 and NaF)-correlated OH-stretch spectra of water at the air/water interface. Vibrational mapping of the perturbed interfacial water with the hydration shell spectra (obtained by DS-SCF analysis of Raman spectra) of the corresponding anion discloses that the kosmotropic electrolytes do not form well-defined EDL at the air/water interface. Instead, the interfacial water forms a stronger hydrogen-bond with the surface-expelled anions (CO32- and F-) and becomes more inhomogeneous than the pristine air/water interface. Together, the results reveal that the perturbation of interfacial water by the kosmotropic electrolyte is a "local phenomenon" confined within the hydration shell of the surface-expelled anion.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::b34a62272836c55f70f55fa69a5abefe https://doi.org/10.1021/acs.jpcb.0c11024 Zobrazit plný text záznamu