Nickel incorporation in Fe(II, III) hydroxysulfate Green Rust: effect on crystal lattice spacing and oxidation products

Revista Brasileira de Ciência do Solo

Lucia Helena Garófalo Chaves²  Joan Elizabeth Curry¹  David Andrew Stone¹  Michael D. Carducci¹  Jon Chorover¹ 

[1] ,Universidade Federal de Campina Grande Department of Agricultural Engineering Campina Grande PB

关键词: isomorphous substitution;    layered double hydroxide;    LDH;    X ray diffraction;    substituição isomórfica;    hidróxido de dupla camada;    HDC;    difração de raios X;   

DOI  :  10.1590/S0100-06832009000500005

来源: SciELO

【 摘 要 】

Ni(II)-Fe(II)-Fe(III) layered double hydroxides (LDH) or Ni-containing sulfate green rust (GR2) samples were prepared from Ni(II), Fe(II) and Fe(III) sulfate salts and analyzed with X ray diffraction. Nickel is readily incorporated in the GR2 structure and forms a solid solution between GR2 and a Ni(II)-Fe(III) LDH. There is a correlation between the unit cell a-value and the fraction of Ni(II) incorporated into the Ni(II)-GR2 structure. Since there is strong evidence that the divalent/trivalent cation ratio in GR2 is fixed at 2, it is possible in principle to determine the extent of divalent cation substitution for Fe(II) in GR2 from the unit cell a-value. Oxidation forms a mixture of minerals but the LDH structure is retained if at least 20 % of the divalent cations in the initial solution are Ni(II). It appears that Ni(II) is incorporated in a stable LDH structure. This may be important for two reasons, first for understanding the formation of LDHs, which are anion exchangers, in the natural environment. Secondly, this is important for understanding the fate of transition metals in the environment, particularly in the presence of reduced Fe compounds.

【 授权许可】

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