Structure and reactivity of synthetic Co-substituted goethites.
In: American Mineralogist, Jg. 93 (2008-04-01), Heft 4, S. 584-584
academicJournal
Zugriff:
A set of synthetic goethites were prepared from Fe 3+ - and Co 2+ -nitrate solutions in alkaline media with a Co/(Co + Fe) ratio (x Co ) 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 x Co <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 x Co . 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. [ABSTRACT FROM AUTHOR]
Copyright of American Mineralogist is the property of De Gruyter and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
Titel: |
Structure and reactivity of synthetic Co-substituted goethites.
|
---|---|
Autor/in / Beteiligte Person: | Alvarez, Mariana ; Sileo, Elsa E. ; Rueda, Elsa H. |
Zeitschrift: | American Mineralogist, Jg. 93 (2008-04-01), Heft 4, S. 584-584 |
Veröffentlichung: | 2008 |
Medientyp: | academicJournal |
ISSN: | 0003-004X (print) |
DOI: | 10.2138/am.2008.2608 |
Schlagwort: |
|
Sonstiges: |
|