Electrical Double-Layer Structure at the Rutile–Water Interface as Observed in Situ with Small-Period X-Ray Standing Waves

Atomistic computer simulation of the clay–fluid interface in colloidal laponite

“…X-ray standing wave studies of the rutile-water interface provide quite detailed information on the counterion distribution. 7 Recent studies on rubidium ions show a large population in the innersphere, probably due to the very weak hydration of this cation. 24 For us to understand the thermodynamics of the confined water, it is important to establish the interlayer density.…”

“…However, recent experiments have shown that for surface-surface separations less than 30 Å the molecular nature of water and the hydrated species dominates the structure and interactions. [3][4][5][6][7] In this regime atomistic level computer simulations can play a very valuable role by providing detailed portraits of the interfacial aqueous phase.…”

Inner-sphere complexation of cations at the rutile–water interface: A concise surface structural interpretation with the CD and MUSIC model

“…Molecular-scale surface structural information of the interaction of water and ion adsorption at metal-oxide surfaces, such as TiO 2 and various Fe(hydr)oxides, is available from in situ small-period X-ray standing wave measurements (Fenter et al, 2000(Fenter et al, , 2002, and references therein), grazing-incidence X-ray absorption (GI-XAF) spectroscopy (Towle et al, 1999a,b), and EXAFS (Axe et al, 1998;Ragnarsdottir et al, 1998;Brown et al, 1999;Sahai et al, 2000). Measurements with these techniques reveal precise structural information on the coordination geometry of specifically adsorbed ions.…”

“…The adsorption of so-called ''inert electrolyte" ions are typically treated as being exclusively non-specific and outer-sphere. However, X-ray spectroscopy has revealed that electrolyte cations can form inner-sphere complexes at the (1 1 0) face of rutile (Fenter et al, 2000;Zhang et al, 2004Zhang et al, , 2007. Moreover, the observed structures have been incorporated into a few previous modeling efforts (Zhang et al, 2004;Ridley et al, 2005).…”

Mineral-Aqueous Solution Interfaces and Their Impact on the Environment

“…Of relevance here is XAFS spectroscopy, because it is well suited for molecular-level studies of adsorption complexes at mineral-water interfaces (Section 5 .2) . A number of other synchrotron-based methods can provide complementary information about mineral-water interfaces and these include X-ray fluorescence microprobe imaging (e.g ., Bertsch and Hunter, 2001), scanning transmission X-ray microscopy imaging and nanospectroscopy (e.g ., Benzerara et al ., 2004Benzerara et al ., , 2005Benzerara et al ., , 2006aBenzerara et al ., ,b, 2008Benzerara et al ., , 2010Benzerara et al ., , 2011aBernard et al ., 2007Bernard et al ., , 2009Bernard et al ., , 2010Couradeau et al ., 2012); X-ray photoelectron spectroscopy (e.g ., Liu et al ., 1998a,d), X-ray standing wave fluorescent yield spectroscopy (e.g ., Fenter et al ., 2000aFenter et al ., ,b, 2003aTempleton et al ., 2001Templeton et al ., , 2003aCatalano et al ., 2006), surface X-ray scattering (crystal truncation rod, CTR, diffraction;e.g ., Eng et al ., 2000;Trainor et al ., 2004); X-ray reflectivity and resonant anomalous X-ray reflectivity (RAXR; e.g ., Teng et al ., 2001;Catalano et al ., 2008;Fenter et al ., 2007Fenter et al ., , 2008, and high energy total X-ray scattering and pair distribution function analysis (Michel et al ., 2007a,b; . All of these new methods have also led to new understanding of Earth materials, particularly those consisting of complex mixtures of solids, liquids, and microbial organisms .…”