Hydrothermal Synthesis Mg-Al Layered Double Hydroxides and Selectivity of Crystal Growth Direction

The magnesium-aluminium layered double hydroxides(Mg-Al LDHs)has been successfully synthesized by the hydrothermal approach,using MgO,Al(OH)3 as the starting materials.The influences of the reaction conditions(including hydrothermal time and hydrothermal temperature)on the crystal structure and selectivity of crystal growth in different directions of the products were investigated by X-ray diffraction and scanning electron microscopy.It has been shown that with increasing the hydrothermal time at the same hydrothermal temperature or increasing the hydrothermal temperature at the same hydrothermal time the crystallization of the LDHs increased and the particle size became larger.The size of the crystallites in direction a was larger than that in the direction c under all experimental conditions.