Structural, vibrational and morphological properties of layered double hydroxides containing Ni2Â +, Zn2Â +, Al3Â + and Zr4Â + cations

Layered double hydroxides are anionic clays with formula [MII1 − x MIIIx(OH)2]q +[An −]q/n·mH2O, finding possible uses as catalyst support, adsorbents and so on. In this paper, we address the phase formation of layered double hydroxides containing Ni2 +, Zn2 +, Al3 + and Zr4 + cations, namely, NiZn-Al, NiZn-AlZr and NiZn-Zr compositions obtained by the coprecipitation method. Such systems were characterized by X-ray diffraction, confirming the phase formation for NiZn-Al and NiZn-AlZr samples. Infrared and Raman spectroscopies elucidated the anion and water molecules occurrence in the interlayer. Nitrogen physisorption (BET method) determined the presence of pores and specific surface area. The isotherm shapes were Type IV, according to the IUPAC, and represent a mesoporous structure. A morphological study was performed by means of scanning and transmission electron microscopies, and particle size values of 120, 131 and 235 nm for NiZn-Al, NiZn-AlZr and NiZn-Zr, respectively, were determined. Thermogravimetric analysis of the decomposition of the systems revealed that their complete disintegration occurred at ~ 450 °C and resulted in mixed oxides.