Interfacial electron transfer in colloidal spinel iron oxide. Conversion of Fe3O4-γFe2O3 in aqueous medium

https://doi.org/10.1016/0021-9797(88)90036-7Get rights and content

Abstract

The behaviour of colloidal Fe3O4 (∼100 Å) in weakly acidic medium (pH 2-2.5) has been investigated by potentiometry, X-ray diffraction, and Mössbauer spectroscopy. Complete and exclusive removal of FeII without noticeable particle size effect is reported. Subsequent Fe3O4 → γFe2O3 transformation is suggested to proceed with selective surface leaching of FeII ions reduced by electron core-to-surface transfer. An analogous conversion is experienced in the presence of FeIII in solution, but it is characterized by significant structural disordering in the surface.

References (44)

  • V.I.E Bruyere et al.

    J. Electroanal. Chem.

    (1985)
  • M.A Blesa et al.

    J. Colloid Interface Sci.

    (1984)
  • D.R Dixon

    Colloids and Surfaces

    (1985)
  • A.E Regazzoni et al.

    J. Colloid Interface Sci.

    (1983)
  • M.A Blesa et al.

    J. Colloid Interface Sci.

    (1984)
  • P.S Sidhu et al.

    J. Inorg. Nucl. Chem.

    (1977)
  • E Tronc et al.

    Mater. Res. Bull.

    (1982)
  • S Mørup

    J. Magn. Magn. Mater.

    (1983)
  • G.Y Onoda et al.

    Surface Sci.

    (1966)
  • M.M Benjamin et al.

    J. Colloid Interface Sci.

    (1981)
  • J Lyklema

    Electroanal. Chem.

    (1968)
  • J.W Perram et al.

    Austral. J. Chem.

    (1974)
  • M.A Blesa et al.

    J. Chim. Phys.

    (1986)
  • G.C Allen et al.

    Philos. Mag. Lett.

    (1983)
  • N Valverde et al.

    Ber. Bunsenges. Phys. Chem.

    (1976)
  • P.H Tewari et al.

    Canad. J. Chem.

    (1972)
  • H Tamura et al.

    J. Colloid Interface Sci.

    (1982)
  • D.P Benton et al.

    J. Chem. Soc.

    (1962)
  • S.M Ahmed et al.

    Canad. J. Chem.

    (1968)
  • J.P Jolivet et al.

    Nouv. J. Chim.

    (1983)
  • E Tronc et al.

    J. Chem. Soc., Faraday Trans. 1

    (1984)
  • H Topsøe et al.

    J. Phys.

    (1974)
  • Cited by (168)

    View all citing articles on Scopus
    View full text