Soil Science Society of America Journal · 1975 · 348 citations · 0 references
Natural SciencesChemistryEarth SciencesInorganic ChemistrySurface ChemistrySurface ScienceIron HydroxidesIron OxidesMineral ChemistryMineral Surface ChemistrySurface AdsorptionSurface ReactionsAdsorption On Iron HydroxidesCoordinationOxyhydroxide Surface ComplexationPhosphate FixationPhosphate SorptionPhosphorus AdsorptionSurface Reaction MechanismsSurface Reaction Pathways
Abstract Infrared spectroscopic techniques have been used to obtain a structural model for the surface reaction between iron oxides and phosphate ions. Two surface hydroxyl ions (or water molecules) are replaced by one phosphate ion. Two of the oxygen atoms of the phosphate ion are coordinated, each to a different Fe 3+ ion, resulting in a binuclear surface complex of the type Fe‐O‐P(O 2 )‐O‐Fe. Evidence is given for phosphate adsorption producing this coordination structure on the surfaces of goethite, hematite, lepidocrocite, β‐ferric hydroxide, and amorphous ferric hydroxide gel.