Skip to Main content Skip to Navigation
Journal articles

Fast Precipitation of Acicular Goethite from Ferric Hydroxide Gel under Moderate Temperature (30 and 70 °C)

German Montes-Hernandez 1 Pierre Beck 2 François Renard 3 Eric Quirico 2 Bruno Lanson 1 R. Chiriac 4 Nathaniel Findling 1
1 Minéralogie et environnements [?-2015]
ISTerre [2011-2015] - Institut des Sciences de la Terre [2011-2015] : UMR5275
2 Planéto
IPAG - Institut de Planétologie et d'Astrophysique de Grenoble
3 Mécanique des failles [?-2015]
ISTerre [2011-2015] - Institut des Sciences de la Terre [2011-2015]
Abstract : The present study describes a simple and novel synthesis route for submicrometric acicular goethite (α-FeOOH) using high OH/Fe molar ratio (=5) and moderate temperature (30 and 70 °C). Two different alkaline sources (NaOH and Ca(OH)2) and two iron(III) sources (FeCl3*6H2O and Fe(NO3)3.9H2O) were investigated. FESEM, XRD, FTIR, N2 sorption isotherms, color evolution, and pH monitoring have been used to determine the formation mechanism, the particle size, specific surface area, and morphology of goethite particles. Three pH regions were determined during goethite formation, and each of them was qualitatively associated to (I) the formation of a ferric hydroxide gel, leading to acid conditions (pH < 2.5); (II) the spontaneous nucleation of goethite, leading to alkaline conditions (pH > 11) and fine sedimentable particles; and (III) the growth of goethite in alkaline conditions (11 < pH < 13.5). Both the temperature and the Fe(III) source have a significant effect on the particle size, specific surface area, and morphology of goethite. High acicular goethite particles (<1 μm in length, moderate specific surface area, SBET = 31.2 m2/g) were produced after 7 h of reaction at 70 °C, while about 24 h of reaction are required to produce low acicular goethite particles (<0.5 μm in length, high specific surface area, SBET = 133.8 m2/g) at 30 °C, using in both cases iron chloride. When Ca(OH)2 particles are used as alkaline source, a complex mineral composite with high specific surface area (87.3 m2/g) was synthesized; it was mainly composed of unreacted Ca(OH)2 coated with nanosized particles (possibly amorphous iron hydroxide), calcium iron oxide chloride hydrate, and calcite. Novel conditions to prepare uniform goethite particles, possibly with high potential as adsorbents or pigments, have been established.
Document type :
Journal articles
Complete list of metadatas

https://hal-insu.archives-ouvertes.fr/insu-00645437
Contributor : Pascale Talour <>
Submitted on : Monday, November 28, 2011 - 10:04:41 AM
Last modification on : Wednesday, October 14, 2020 - 4:02:51 AM

Identifiers

Collections

Citation

German Montes-Hernandez, Pierre Beck, François Renard, Eric Quirico, Bruno Lanson, et al.. Fast Precipitation of Acicular Goethite from Ferric Hydroxide Gel under Moderate Temperature (30 and 70 °C). Crystal Growth and Design, American Chemical Society, 2011, 11 (6), pp.2264-2272. ⟨10.1021/cg1016802⟩. ⟨insu-00645437⟩

Share

Metrics

Record views

485