Hostname: page-component-848d4c4894-ndmmz Total loading time: 0 Render date: 2024-05-29T11:53:24.252Z Has data issue: false hasContentIssue false
  • English
  • Français

Distinguishing Between Surface and Bulk Dehydration-Dehydroxylation Reactions in Synthetic Goethites by High-Resolution Thermogravimetric Analysis

Published online by Cambridge University Press:  28 February 2024

Robert G. Ford  and
Paul M. Bertsch
Robert G. Ford*
Affiliation:
Advanced Analytical Center for Environmental Science, Savannah River Ecology Laboratory, University of Georgia, P.O. Drawer E, Aiken, South Carolina 29802, USA
Paul M. Bertsch
Affiliation:
Advanced Analytical Center for Environmental Science, Savannah River Ecology Laboratory, University of Georgia, P.O. Drawer E, Aiken, South Carolina 29802, USA
*
†Current Address: University of Delaware, Department of Plant and Soil Sciences, Newark, Delaware 19717, USA.
Get access Rights & Permissions [Opens in a new window]

Abstract

Synthetic goethites studied by high-resolution thermogravimetry (HRTGA) show variability in surface characteristics and structural stability as a function of aging conditions. Goethites were synthesized at either pH 6 or 11, at temperatures of 40 or 70°C, and in the presence or absence of sorbed Mn or Pb. Data from HRTGA analysis revealed at least four distinct weight-loss events near goethite dehydroxylation that relate to 1) three events involving the evolution of water associated with surface Fe-O functional groups and 2) bulk dehydroxylation of goethite during transformation to hematite. The relative mass of evolved surface and bulk structural water was related to the predominant particle morphology as determined by transmission electron microscopy (TEM). Differentiation of surface and bulk decomposition reactions allowed the identification of bulk structural dehydroxylation. Goethite crystallin-ity, estimated by the bulk dehydroxylation temperature, appeared to depend on the kinetics of crystallization. This trend was most evident for systems aged at pH 11 and 40°C. Greater concentrations of coprecipitated Mn or Pb dramatically improved goethite crystallinity as indicated by higher dehydroxylation temperatures and smaller widths of the (110) Bragg reflection. Comparison of bulk dehydroxylation temperatures for these samples to other preparations suggests that structural defects predominated over the effects of particle size and Mn/Pb substitution in determining goethite thermal stability. A conceptual model is proposed to account for the disparate dehydroxylation profiles displayed by goethites of varying crystallinity.

Keywords

CrystallinityDehydroxylationGoethiteThermogravimetryNonstoichiometric WaterTEMXRD
Type
Research Article
Information
Clays and Clay Minerals , Volume 47 , Issue 3 , June 1999 , pp. 329 - 337
Copyright
Copyright © 1999, The Clay Minerals Society

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Anonymous, 1997 Appendix B: High resolution TGA option TGA 2950 Thermogravimetric Analyzer Operator’s Manual.Google Scholar
Bruemmer, G.W. Gerth, J. and Tiller, K.G., 1988 Reaction kinetics of the adsorption and desorption of nickel, zinc and cadmium by goethite. I. Adsorption and diffusion of metals Journal of Soil Science 39 37–52 10.1111/j.1365-2389.1988.tb01192.x.CrossRefGoogle Scholar
Cambier, P., 1986 Infrared study of goethites of varying crystallinity and particle size: II. Crystallographic and morphological changes in series of synthetic goehites Clay Minerals 21 201–210 10.1180/claymin.1986.021.2.09.CrossRefGoogle Scholar
Cambier, P., 1986 Infrared study of goethites of varying crystallinity and particle size: I. Interpretation of OH and lattice vibration frequencies Clay Minerals 21 191–200 10.1180/claymin.1986.021.2.08.CrossRefGoogle Scholar
Colombo, C. Barron, V. and Torrent, J., 1994 Phosphate adsorption and desorption in relation to morphology and crystal properties of synthetic hematites Geochimica et Cosmochimica Acta 58 1261–1269 10.1016/0016-7037(94)90380-8.CrossRefGoogle Scholar
Cornell, R.M. and Giovanoli, R., 1985 Effect of solution conditions on the proportion and morphology of goethite formed from ferrihydrite Clays and Clay Minerals 33 424–432 10.1346/CCMN.1985.0330508.CrossRefGoogle Scholar
Cornell, R.M. and Giovanoli, R., 1986 Factors that govern the formation of multi-domainic goethites Clays and Clay Minerals 34 557–564 10.1346/CCMN.1986.0340509.CrossRefGoogle Scholar
Cornell, R.M. Giovanoli, R. and Schneider, W., 1989 Review of the hydrolysis of iron (III) and the crystallization of amorphous iron(III) hydroxide hydrate Journal of Chemical Technology and Biotechnology 46 115–134 10.1002/jctb.280460204.CrossRefGoogle Scholar
Cornell, R.M. Posner, R.M. and Quirk, J.P., 1974 Crystal morphology and the dissolution of goethite Journal of Inorganic and Nuclear Chemistry 36 1937–1946 10.1016/0022-1902(74)80705-0.CrossRefGoogle Scholar
Cornell, R.M. and Schneider, W., 1989 Formation of goethite from ferrihydrite at physiological pH under the influence of cysteine Polyhedron 8 149–155 10.1016/S0277-5387(00)86496-7.CrossRefGoogle Scholar
de Delhez, R. Keijser, T.H. Mittemeijer, E.J. and Langford, J.I., 1988 Size and strain parameters from peak profiles: Sense and nonsense Australian Journal of Physics 41 213–227 10.1071/PH880213.CrossRefGoogle Scholar
Domingo, C. Rodriguez-Clemente, R. and Blesa, M., 1994 Morphological properties of α-FeOOH, γ-FeOOH, and Fe3O4 obtained by oxidation of aqueous Fe(II) solutions Journal of Colloid and Interface Science 165 244–252 10.1006/jcis.1994.1225.CrossRefGoogle Scholar
Fey, M.V. and Dixon, J.B., 1981 Synthesis and properties of poorly crystalline hydrated aluminous goethites Clays and Clay Minerals 29 91–100 10.1346/CCMN.1981.0290202.CrossRefGoogle Scholar
Forsyth, J.B. Hedley, L.G. and Johnson, C.E., 1968 The magnetic structure and hyperfine field of goethite (α-FeOOH) Journal of Physics C 1 179–188 10.1088/0022-3719/1/1/321.CrossRefGoogle Scholar
Gasser, U.G. Jeanroy, E. Mustin, C. Barres, O. Nuesch, R. Berthelin, J. and Herbillon, A.J., 1996 Properties of synthetic goethites with Co for Fe substitution Clay Minerals 31 465–477 10.1180/claymin.1996.031.4.03.CrossRefGoogle Scholar
Giovanoli, R. and Cornell, R.M., 1992 Crystallization of metal substituted ferrihydrites Zeitschrift fur Pflanzenernahrung und Bodenkunde 155 455–460 10.1002/jpln.19921550517.CrossRefGoogle Scholar
Goss, C.J., 1987 The kinetics and reaction mechanism of the goethite to hematite transformation Mineralogical Magazine 51 437–451 10.1180/minmag.1987.051.361.11.CrossRefGoogle Scholar
de Hiemstra, T. van Wit, J. and Riemsdijek, W., 1989 Multisite proton adsorption modeling at the solid/solution interface of (hydr)oxides: A new approach II. Application to various important (hydr)oxides Journal of Colloid and Interface Science 133 104–117 10.1016/0021-9797(89)90285-3.CrossRefGoogle Scholar
Kuhnel, R.A. Roorda, H.J. and Steensma, J.J., 1975 The crystallinity of minerals-A new variable in pedogenetic processes: A study of goethite and associated silicates in laterites Clays and Clay Minerals 23 349–354 10.1346/CCMN.1975.0230503.CrossRefGoogle Scholar
Mackenzie, R.C. Paterson, E. and Swaffield, R., 1981 Observation of surface characteristics by DSC and DTA Journal of Thermal Analysis 22 269–274 10.1007/BF01915274.CrossRefGoogle Scholar
Manceau, A. and Gates, W.P., 1997 Surface structural model for ferrihydrite Clays and Clay Minerals 45 448–460 10.1346/CCMN.1997.0450314.CrossRefGoogle Scholar
Mann, S. Cornell, R.M. and Schwertmann, U., 1985 The influence of aluminium on iron oxides: XII. High-resolution transmission electron microscopic (HRTEM) study of aluminous goethites Clay Minerals 20 255–262 10.1180/claymin.1985.020.2.09.CrossRefGoogle Scholar
Maurice, P.A. Hochella, M.F. Jr Parks, G.A. Sposito, G. and Schwertmann, U., 1995 Evolution of hematite surface microtopography upon dissolution by simple organic acids Clays and Clay Minerals 43 29–38 10.1346/CCMN.1995.0430104.CrossRefGoogle Scholar
Parfitt, R.L. Russell, J.D. and Farmer, V.C., 1975 Confirmation of the surface structures of goethite (α-FeOOH) and phosphated goethite by infrared spectroscopy Journal of the Chemical Society Faraday Transactions I 72 1082–1087 10.1039/f19767201082.CrossRefGoogle Scholar
Paterson, E. and Swaffield, R., 1980 Influence of adsorbed anions on the dehydroxylation of synthetic goethite Journal of Thermal Analysis 18 161–167 10.1007/BF01909464.CrossRefGoogle Scholar
Reynolds, R.C., Bish, D.L. and Post, J.E., 1989 Diffraction by small and disordered crystals Modern Powder Diffraction 145–181 10.1515/9781501509018-009.CrossRefGoogle Scholar
Rochester, C.H. and Topham, S.A., 1978 Infrared study of surface hydroxyl groups on goethite Journal of the Chemical Society Faraday Transactions I 75 591–602 10.1039/f19797500591.CrossRefGoogle Scholar
Russell, J.D. Parfitt, R.L. Fraser, A.R. and Farmer, V.C., 1974 Surface structures of gibbsite, goethite, and phosphated goethite Nature 248 220–221 10.1038/248220a0.CrossRefGoogle Scholar
Rustad, J.R. Felmy, A.R. and Hay, B.P., 1996 Molecular statics calculation of proton binding to goethite surfaces: A new approach to estimation of stability constants for mul-tisite surface complexation models Geochimica et Cos-mochimica Acta 60 1563–1576 10.1016/0016-7037(96)00035-X.CrossRefGoogle Scholar
Sampson, C.F., 1969 The lattice parameters of natural single crystal and synthetically produced goethite (α-FeOOH) Acta Crystallographica B25 1683–1685 10.1107/S0567740869004559.CrossRefGoogle Scholar
Schulze, D.G., 1984 The influence of aluminum on iron oxides. VIII. Unit-cell dimensions of Al-substituted goethites and estimation of A1 from them Clays and Clay Minerals 32 36–44 10.1346/CCMN.1984.0320105.CrossRefGoogle Scholar
Schulze, D.G. and Schwertmann, U., 1984 The influence of aluminum on iron oxides: X. Properties of Al-substituted goethites Clay Minerals 19 521–539 10.1180/claymin.1984.019.4.02.CrossRefGoogle Scholar
Schulze, D.G. and Schwertmann, U., 1987 The influence of aluminum on iron oxides: XIII. Properties of goethites synthesized in 0.3 M KOH at 25°C Clay Minerals 22 83–92 10.1180/claymin.1987.022.1.07.CrossRefGoogle Scholar
Schwertmann, U. and Murad, E., 1983 Effect of pH on the formation of goethite and hematite from ferrihydrite Clays and Clay Minerals 31 277–284 10.1346/CCMN.1983.0310405.CrossRefGoogle Scholar
Schwertmann, U., 1984 The influence of aluminum on iron oxides: IX. Dissolution of Al-goethites in 6 M HCl Clay Minerals 19 9–19 10.1180/claymin.1984.019.1.02.CrossRefGoogle Scholar
Schwertmann, U., 1984 The double dehydroxylation peak of goethite Thermochimica Acta 78 39–46 10.1016/0040-6031(84)87130-0.CrossRefGoogle Scholar
Schwertmann, U. Cambier, P. and Murad, E., 1985 Properties of goethites of varying crystallinity Clays and Clay Minerals 33 369–378 10.1346/CCMN.1985.0330501.CrossRefGoogle Scholar
Schwertmann, U. Taylor, R.M., Dixon, J.B. and Weeds, S.B., 1989 Iron oxides Minerals in Soil Environments 379–438.CrossRefGoogle Scholar
Schwertmann, U., Boot, MF d Hayes, M.H.B. and Herbillon, A., 1990 Some properties of soil and synthetic iron oxides Soil Colloids and Their Associations in Aggregates 57–103 10.1007/978-1-4899-2611-1_3.CrossRefGoogle Scholar
Schwertmann, U. and Cornell, R.M., 1991 Iron Oxides in the Laboratory: Preparation and Characterization .Google Scholar
Sposito, G., 1984 The Surface Chemistry of Soils .Google Scholar
Wolska, E. and Schwertmann, U., 1993 The mechanism of solid solution formation between goethite and diaspore Neues Jahrbuch fur Mineralogie-Monatshefte 5 213–223.Google Scholar