Preparation and intercalation reactions of Zn-Sn LDH and Zn-Al-Sn LDH

Layered double hydroxide (LDH) is synthesized conventionally only with divalent and trivalent cations. In this study, Zn-Sn LDH consisting of di- and tetra-valent cations and Zn-Al-Sn LDH consisting of di-, tri- and tetra-valent cations were prepared and reacted with organic monocarboxylic, dicarboxylic and aromatic acids at 60degreesC. The 003 spacing of the prepared LDH (Zn-Sn-CO3) is 0.67 nm which is smaller compared to that of the usual LDH (Zn-Al-CO3) with 0.76 nm in the case of carbonate anion as the guest. Zn-Al-Sn-CO3 LDH has two 003 spacings i.e., 0.67 and 0.75 nm which belong to Zn-Sn-CO3 and Zn-Al-CO3 LDH, respectively. Analysis by DTA, TG and DTG indicated that the electrostatic force between the Zn-Sn layers and carbonate anions is larger than that of Zn-Al LDH. The carbonate anions in Zn-Sn LDH decomposed at 261degreesC while in the usual LDH they decomposed at 230-240degreesC.