Hydrothermal Synthesis, Structural Analysis and Performance of Regular Mn-Zn-Mg-Al-CO3 Quaternary Layered Double Hydroxides (LDHs)

Regular Mn-Zn-Mg-Al-CO3 quaternary layered double hydroxides(LDHs) were synthesized by hydrothermal method in one step, using Mn(NO3)(2)center dot 6H(2)O, Zn(NO3)(2)center dot 6H(2)O, Mg(NO3)(2)center dot 6H(2)O and Al(NO3)(3)center dot 9H(2)O as raw materials. ICP, Elemental Analysis, XRD, IR, TG-DSC, SEM, low temperature nitrogen adsorption-desorption were used to characterize the composition, crystallinity, structure, morphology and performance of the obtained materials. The effects of pH value, reaction temperature, reaction time, molar ratio of raw materials on the structure of Mn-Zn-Mg-Al-CO3 quaternary LDHs were investigated. The results show that Mn-Zo-Mg-Al-CO3 quaternary LDHs with well-defined shape, obvious intercalated structure and well regular quality could be obtained at pH value about 10, the hydrothermal temperature of 140 degrees C and reaction time of 24 h. The nitrogen adsorption-desorption results suggest that the isothermal type of the sample is type V, hysteresis loop resembls the H3-type in the WAG classification. The samples have highly ordered intimate structure, neatly arranged interlayer anions, high hole density, small aperture and large surface area.