Raman spectroscopy study of layered-double hydroxides containing magnesium and trivalent metals

We examined the Raman spectra for LDHs containing Mg2+ and a trivalent metal (Al3+, Ga+ or In+) with an Mg2+/M3+ ratio of 3. The Raman spectra exhibited very strong signals at ca. 1060 cm(-1), 540 cm(-1) and 150 cm(-1) that were ascribed to symmetric stretching of interlayer carbonate ions, symmetric stretching of Mg-O-Mg bonds in Mg-3(OH) structural units and stretching of M-O bonds, respectively. The spectra additionally contained various weaker signals suggesting that the LDHs studied consist solely of Mg-3(OH) and Mg(OH)(2)M(III)O structural units. (C) 2014 Elsevier B.V. All rights reserved.