Structural characterization and thermal behavior of Ni/Mg/Al layered double hydroxides

Ni/Mg/Al LDHs with different molar ratios have been prepared by coprecipitation method. Their structure has been characterized by X-ray diffraction (XRD). LDHs with the highest Ni content show the lowest crystallinity. Their thermal decomposition behavior has been investigated using thermogravimetry analysis (TGA) and XRD. Ni content introduced into the brucite-like layers and [Ni²⁺ + Mg²⁺]/Al³⁺ molar ratio of LDHs samples qffects the thermal behavior of LDHs. Thermal decomposition temperature of brucite-like layer OH and interlayer CO₃^2- anion increases with decreasing Ni content and increasing [Ni²⁺ + Mg²⁺]/Al³⁺ molar ratio. Loss of interlayer water is most difficult for NiMg ₂Al-LDHs. The thermal treatment of LDHs precursors resulted in the formation of mixed oxides phase at temperature above 400°C.