Electrolyte layering at the calcite(104)-water interface indicated by Rb+- and Se(VI) K-edge resonant interface diffraction
- Karlsruher
Calcite–water interface reactions are of major importance in various environmental settings as well as in industrial applications. Here we present resonant interface diffraction results on the calcite(104)–aqueous solution interface, measured in solutions containing either 10 mmol L-1 RbCl or 0.5 mmol L-1 Se(VI). Results indicate that Rb+ ions enter the surface adsorbed water layers and adsorb at the calcite(104)–water interface in an inner-sphere fashion. A detailed analysis based on specular and off-specular resonant interface diffraction data reveals three distinct Rb+ adsorption species: one 1.2 Å above the surface, the second associated with surface adsorbed water molecules 3.2 Å above the surface, and the third adsorbed in an outer-sphere fashion 5.6 Å above the surface. A peak in resonant amplitude between L = 1.5 and L = 3.0 is interpreted as signal from a layered electrolyte structure. The presence of a layered electrolyte structure seems to be confirmed by data measured in the presence of Se(VI).
- Research Organization:
- Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source (APS)
- Sponsoring Organization:
- FOREIGN
- OSTI ID:
- 1151852
- Journal Information:
- Phys. Chem. Chem. Phys., Vol. 16, Issue (25) ; 2014
- Country of Publication:
- United States
- Language:
- ENGLISH
Similar Records
inner-sphere complexation of cations at the rutile-water interface: A concise surface structural interpretation with the CD and MUSIC model
Surface Charge of the Calcite (104) Terrace Measured by Rb + Adsorption in Aqueous Solutions Using Resonant Anomalous X-ray Reflectivity