Ternary VO2+-ligand-surface complexes on boehmite and noncrystalline aluminosilicates
01 Dec 1987-Vol. 120, Iss: 2, pp 419-429
TL;DR: In this article, electron spin resonance (ESR) spectroscopy was used to characterize the ligand environment of VO 2+ absorbed on boehmite and noncrystalline aluminosilicates.
Abstract: Electron spin resonance (ESR) spectroscopy was used to characterize the ligand environment of VO 2+ absorbed on boehmite and noncrystalline aluminosilicates. Boehmite possessed a relatively low capacity to chemisorb VO 2+ at discrete sites at low pH, a fact attributed to the chemical inactivity of the dominant (020) surfaces of the mineral. The chemisorbed cation is rigidly bound by one or two surface oxyanions. Chemisorption on allophane produced slightly different ESR parameters for VO 2+ , a possible consequence of the participation of silanol groups in the metal-surface bond. Evidence for ternary surface complexes was seen upon the addition of phosphate to the VO 2+ -surface complexes, with changes occurring in the ESR spectrum of bound VO 2+ . Oxalate also appeared to perturb the ligand environment of sorbed VO 2+ , but other anionic species had little or no effect. The experimental results point to the coadsorption of a vanadyl-phosphate complex, in which both the VO 2+ and the PO 4 3− are chemisorbed to surface Al atoms. The ESR spectra of VO 2+ in model phosphate compounds are used to establish the effect of PO 4 3− coordination with VO 2+ on the spectral parameters.
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Environmental Molecular Sciences Laboratory1, Yale University2, University of California, Davis3, Los Alamos National Laboratory4, University of Wyoming5, Texas A&M University6, École Polytechnique Fédérale de Lausanne7, Colorado State University8, California Institute of Technology9, Johns Hopkins University10, IBM11
TL;DR: This poster presents a probabilistic procedure to constrain the number of particles in the response of the immune system to the presence of Tau.
Abstract: Reference LPI-ARTICLE-1999-017View record in Web of Science Record created on 2006-02-21, modified on 2017-05-12
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01 Jan 1989
TL;DR: In this paper, a more fundamental understanding of the soil processes controlling metal solubility is proposed to prevent practices that could have deleterious effects on soil productivity and environmental quality.
Abstract: Soil chemists have long-recognized that knowledge of the elemental composition of soils is generally of little use in assessing the availability of these elements to plants. An obvious illustration of this principle is the common occurrence of Fe and Mn deficiency in plants despite the relatively high levels of Fe and Mn in many soils. For this reason, chemical soil tests have relied on measurement of extractable or “labile” fractions of elements. Such tests are empirical and provide little basis to relate metal extractability to the chemical forms of the metal in the soil. As soils are increasingly used in our society for purposes other than agriculture, the frequency and extent of soil contamination by toxic metals will increase. Empirical relationships may have to be replaced by a more fundamental understanding of the soil processes controlling metal solubility to prevent practices that could have deleterious effects on soil productivity and environmental quality.
664 citations
TL;DR: Extended X-ray Absorption Fine Structure (EXAFS) spectroscopic data for Cd2+ sorbed on goethite in the presence of phosphate, sulphate and humate indicate that cadmium is surrounded by a first shell of ∼6 ± 1 O atoms at 2.3 ± 0.1 A, and a second shell of approximately 2 Fe atoms at 3.8 ± 1 A is also observed as mentioned in this paper.
204 citations
01 Jan 1991
TL;DR: In this paper, the basic mechanisms of metal ion sorption and desorption are deduced from physical and chemical measurements of the adsorbate-adsorbent interaction, focusing on the transition and heavy metals, which are potential pollutants in soils and soil leachates.
Abstract: Progress in understanding the nature of ion bonding at mineral surfaces in soils has necessitated the use of modern spectroscopy to complement less direct information such as sorption data and surface charge measurements. This review describes the basic mechanisms of metal ion sorption and desorption as they are deduced from physical and chemical measurements of the adsorbate-adsorbent interaction. Emphasis is placed upon the transition and heavy metals, which are potential pollutants in soils and soil leachates.
57 citations
TL;DR: A review of the recent applications of electron spin resonance spectroscopies in surface science can be found in this article, where a table is added to each section with references to the works published in the last few years.
19 citations
References
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01 Jan 1972
TL;DR: In this article, inorganic chemistry principles of structure and reactivity are presented. But, they do not cover how to use these principles in the design of products, and they are not available in any type of product.
Abstract: INORGANIC CHEMISTRY PRINCIPLES OF STRUCTURE AND REACTIVITY JAMES E HUHEEY PDF Are you looking for Ebook inorganic chemistry principles of structure and reactivity james e huheey PDF ? You will be glad to know that right now inorganic chemistry principles of structure and reactivity james e huheey PDF is available on our online library. With our online resources, you can find inorganic chemistry principles of structure and reactivity james e huheey or just about any type of ebooks, for any type of product.
2,814 citations
TL;DR: In this article, measurements were made of the adsorption of cobalt, copper, manganese, nickel, lead, and zinc on nine synthetic manganous oxides and three synthetic iron oxides, to determine the mechanism by which lead accumulates in the MANGANESE oxides in soils.
Abstract: Measurements were made of the adsorption of cobalt, copper, manganese, nickel, lead, and zinc on nine synthetic manganese oxides and three synthetic iron oxides, to determine the mechanism by which lead accumulates in the manganese oxides in soils. Adsorption of lead by the manganese oxides was up to 40 times greater than that by the iron oxides, and lead was adsorbed more strongly than any of the other ions studied by all of the oxides except goethite. This is considered to be the reason for the accumulation of lead in the manganese oxides in soils. No evidence was found for the oxidation of lead, nor for the formation of specific lead-manganese minerals.
704 citations
TL;DR: In this paper, the adsorption data indicate that the primary hydration sphere of free or hydrolyzed metal ions is not altered in the adaption process, and that the qualitative correlation between adsoption and hydrolysis is shown to break down when examined in detail.
521 citations
TL;DR: In this paper, the adsorption of Fe(III, Cu(II), Cd(II, and Pb(II) from aqueous solutions of constant ionic strength at silica-water interfaces was investigated by potentiometric titrations at 25°.
515 citations