Anion Adsorption on Oxide Surfaces:  Inclusion of the Water Dipole in Modeling the Electrostatics of Ligand Exchange

Sverjensky, Dimitri A.; Fukushi, Keisuke

doi:10.1021/es051521v

Cited by 105 publications

(192 citation statements)

References 34 publications

Supporting

Mentioning

185

Contrasting

Order By: Relevance

“…Similar reactions were recently included in consideration by surface complexation models. [13,14] The analysis of the O 1s spectra revealed additional clues on the properties of the hematite surface. The O 1s spectra of the 10 mM suspensions (Fig.…”

Section: Resultsmentioning

confidence: 99%

XPS study of the hematite–aqueous solution interface

Shchukarev

Boily

2008

Surface & Interface Analysis

View full text Add to dashboard Cite

The interaction between the surface of hematite colloidal platelets and Na + and Cl − ions was investigated by XPS using the cryogenic technique. Pastes in ionic strengths of 0 and 10 mM NaCl contained about 10 at. % water and water/NaCl atomic ratios of 3 to 6. These results fall within the range of values obtained for a variety of minerals studied with this technique. Pastes in 100 mM NaCl background electrolyte, however, contained an unusually larger water content of 25 at. %, yielding a Na + : Cl − : H 2 O ratio of 1 : 1 : 2. This result is in strong contrast with other minerals at the same ionic strength, which typically reveal about 10 at. % water. Substituting Na + for Cs + in the hematite paste with 100 mM CsCl yielded, on the other hand, the same amount of water as in the pastes with 0 and 10 mM NaCl, and underpinned the role of Na + ions in the large water content of the hematite paste. As surface concentrations of Na + and Cl − exceeded those of hematite surface structural hydroxyl groups and Na 1s and Cl 2p spectra exhibited energy loss features, the electrolyte ions are proposed to be distributed in a three-dimensional array in the fast-frozen paste, possibly in a hydrohalite-like (NaCl·2H 2 O) phase. In addition, because the fast-frozen solution of 100 mM NaCl yields a water/NaCl ratio of about 70, hematite is proposed to play an important role in the stabilization of this three-dimensional distribution of Na + and Cl − ions. The role of the neutrally charged {001} plane, a predominant feature in the hematite particles of this study, is notably discussed in the light of recent molecular models showing that this plane can stabilize several layers of hydrated ions up to 15 Å from the surface.

show abstract

Section: Resultsmentioning

confidence: 99%

XPS study of the hematite–aqueous solution interface

Shchukarev

Boily

2008

Surface & Interface Analysis

View full text Add to dashboard Cite

show abstract

“…Recent developments in surface complexation modeling enable accurate modeling of surface speciation. Sverjensky and Fukushi (2006) developed an extended triple-layer (ETL) model to account for the process of inner-sphere surface complexation by ligand exchange. The ETL model treats a previously neglected phenomenon integral to ligand exchange reactions: the electrostatic work during desorption of water dipoles from a charged surface.…”

Section: On the Nature Of Mineral -Molecule Interactionsmentioning

confidence: 99%

“…Details of molecular adsorption are dependent on several variables, most notably pH, the nature and concentrations of molecular solutes, and the identities and concentrations of electrolytes (Schindler 1990;Sverjensky 2005;Sverjensky and Fukushi 2006;Jonsson et al 2009). Additional complexities arise when organic molecules interact with crystal surface irregularities (Teng and Dove 1997;Teng et al 1998Teng et al , 2000Orme et al 2001;De Yoreo and Dove 2004;Elhadj et al 2006).…”

Section: On the Nature Of Mineral -Molecule Interactionsmentioning

confidence: 99%

Mineral Surfaces, Geochemical Complexities, and the Origins of Life

Hazen

Sverjensky²

2010

Cold Spring Harbor Perspectives in Biology

275

237

View full text Add to dashboard Cite

Crystalline surfaces of common rock-forming minerals are likely to have played several important roles in life's geochemical origins. Transition metal sulfides and oxides promote a variety of organic reactions, including nitrogen reduction, hydroformylation, amination, and Fischer-Tropsch-type synthesis. Fine-grained clay minerals and hydroxides facilitate lipid self-organization and condensation polymerization reactions, notably of RNA monomers. Surfaces of common rock-forming oxides, silicates, and carbonates select and concentrate specific amino acids, sugars, and other molecular species, while potentially enhancing their thermal stabilities. Chiral surfaces of these minerals also have been shown to separate left-and right-handed molecules. Thus, mineral surfaces may have contributed centrally to the linked prebiotic problems of containment and organization by promoting the transition from a dilute prebiotic "soup" to highly ordered local domains of key biomolecules.

show abstract

“…In the surface complexation calculations we use the term outer-sphere to include true outer-sphere as well as hydrogen-bonded species. The model inner-and outer-sphere species are used as input to an extended triple layer model (ETLM) recently developed to account for the electrostatic effects of water dipole desorption during inner-sphere surface complexation, as well as outer-sphere complexation (Sverjensky and Fukushi, 2006). The basis for application of this model is described below.…”

Section: Introductionmentioning

confidence: 99%