Study on Preparation,Structure and Intercalation Assembly of MgFe-Cl Layered Double Hydroxides

Layered double hydroxides containing Mg2+ and Fe3+ in the brucite-like layers and interlayer chloride ions with an Mg2+/Fe3+ ratio of 2 to 4 were prepared through coprecipitation and characterized by elemental analysis, X-ray diffraction, FT-IR and thermal analysis. By increasing the Mg2+/Fe3+ ratio, a well-crystallized hydrotalcite can be obtained. In the case of the material prepared with Mg2+/Fe3+=4, the interlayer chloride ions may be replaced by either vinylbenzenesulfonate or dodecyl sulfonate ions suggesting that these materials may be useful precursors to MgFe-LDHs intercalated with a variety of organic anions. The interactions between the metal cations and hydroxyl groups in the brucite layer, and between the brucite layers and water in gallery spaces were not affected by Mg2+/Fe3+ molar ratio. The electrostatic interaction between the brucite layers and anions in gallery spaces was reduced by increasing the Mg2+/Fe3+ molar ratio.