Structure and reactivity of synthetic Co-substituted goethites

A set of synthetic goethites were prepared from Fe3+- and Co2+-nitrate solutions in alkaline media with a Co/(Co + Fe) ratio (xCo) up to 10 mol%. The structural characterization of the resultant solid phases was carried out by X-ray diffraction (XRD). XRD analyses showed that in preparations with xC...

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Publicado:	2008
Materias:	Acid dissolution Co-goethite Isomorphous substitution Rietveld refinement chemical composition cobalt crystal chemistry crystal structure dissolution goethite nitrate phase transition Rietveld analysis X-ray diffraction
Acceso en línea:	https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_0003004X_v93_n4_p584_Alvarez http://hdl.handle.net/20.500.12110/paper_0003004X_v93_n4_p584_Alvarez
Aporte de:	Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires

id	paper:paper_0003004X_v93_n4_p584_Alvarez
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spelling	paper:paper_0003004X_v93_n4_p584_Alvarez2023-06-08T14:23:44Z Structure and reactivity of synthetic Co-substituted goethites Acid dissolution Co-goethite Isomorphous substitution Rietveld refinement chemical composition cobalt crystal chemistry crystal structure dissolution goethite nitrate phase transition Rietveld analysis X-ray diffraction A set of synthetic goethites were prepared from Fe3+- and Co2+-nitrate solutions in alkaline media with a Co/(Co + Fe) ratio (xCo) up to 10 mol%. The structural characterization of the resultant solid phases was carried out by X-ray diffraction (XRD). XRD analyses showed that in preparations with xCo <10 mol%, Co-substituted goethite was the only crystalline phase present. Atomic and cell parameters for the samples synthesized were obtained by the Rietveld refinement of the XRD data, and showed that the unit cell in the goethite-like phase is contracted as a function of xCo. Little deviation from the Vegard rule was observed for all unit-cell parameters. Cobalt substitution produces an increase in the surface area of the goethite, as well as an increment in the dehydroxylation temperature. The acid dissolution of all Co-goethites showed an increase in dissolution rate with the Co content, and a congruent behavior was observed. The activation energy for dissolution was obtained two samples. A modified first-order Kabai equation best describes the dissolution data. 2008 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_0003004X_v93_n4_p584_Alvarez http://hdl.handle.net/20.500.12110/paper_0003004X_v93_n4_p584_Alvarez
institution	Universidad de Buenos Aires
institution_str	I-28
repository_str	R-134
collection	Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic	Acid dissolution Co-goethite Isomorphous substitution Rietveld refinement chemical composition cobalt crystal chemistry crystal structure dissolution goethite nitrate phase transition Rietveld analysis X-ray diffraction
spellingShingle	Acid dissolution Co-goethite Isomorphous substitution Rietveld refinement chemical composition cobalt crystal chemistry crystal structure dissolution goethite nitrate phase transition Rietveld analysis X-ray diffraction Structure and reactivity of synthetic Co-substituted goethites
topic_facet	Acid dissolution Co-goethite Isomorphous substitution Rietveld refinement chemical composition cobalt crystal chemistry crystal structure dissolution goethite nitrate phase transition Rietveld analysis X-ray diffraction
description	A set of synthetic goethites were prepared from Fe3+- and Co2+-nitrate solutions in alkaline media with a Co/(Co + Fe) ratio (xCo) up to 10 mol%. The structural characterization of the resultant solid phases was carried out by X-ray diffraction (XRD). XRD analyses showed that in preparations with xCo <10 mol%, Co-substituted goethite was the only crystalline phase present. Atomic and cell parameters for the samples synthesized were obtained by the Rietveld refinement of the XRD data, and showed that the unit cell in the goethite-like phase is contracted as a function of xCo. Little deviation from the Vegard rule was observed for all unit-cell parameters. Cobalt substitution produces an increase in the surface area of the goethite, as well as an increment in the dehydroxylation temperature. The acid dissolution of all Co-goethites showed an increase in dissolution rate with the Co content, and a congruent behavior was observed. The activation energy for dissolution was obtained two samples. A modified first-order Kabai equation best describes the dissolution data.
title	Structure and reactivity of synthetic Co-substituted goethites
title_short	Structure and reactivity of synthetic Co-substituted goethites
title_full	Structure and reactivity of synthetic Co-substituted goethites
title_fullStr	Structure and reactivity of synthetic Co-substituted goethites
title_full_unstemmed	Structure and reactivity of synthetic Co-substituted goethites
title_sort	structure and reactivity of synthetic co-substituted goethites
publishDate	2008
url	https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_0003004X_v93_n4_p584_Alvarez http://hdl.handle.net/20.500.12110/paper_0003004X_v93_n4_p584_Alvarez
_version_	1768544800380813312

Structure and reactivity of synthetic Co-substituted goethites

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