Synthesis and Raman spectroscopic study of Mg/Al,Fe hydrotalcites with variable cationic ratios

摘要: Hydrotalcites of formula Mg6 (Fe,Al)2(OH)16(CO3).4H2O formed by intercalation with the carbonate anion as a function divalent/trivalent cationic ratio have been successfully synthesised. The XRD patterns show variation in d-spacing attributed to size cation. Raman and infrared bands OH stretching region are assigned (a) brucite layer vibrations (b) water (c) strongly hydrogen bonded anion. Multiple (CO3)2- symmetric suggest that different types exist hydrotalcite interlayer. Increasing cation (Mg/Al,Fe) resulted an increase combined intensity 2 at around 3600 cm-1, Mg-OH modes, shift overall band profile higher wavenumbers. These observations believed be result magnesium structure. spectroscopy shows reduction symmetry carbonate, leading conclusion anions brucite-like hydroxyl surface Water bending modes identified spectra positions greater than 1630 indicating is both interlayer surface.