A mechanochemical approach is developed in preparing a series of magnesium–aluminum-layered
double hydroxides (Mg–Al-LDHs). This approach includes a mechanochemical process which involved
manual grinding of solid salts in an agate mortar and afterwards peptization process. In order to verify
the LDHs structure synthesized in the grinding process, X-ray diffraction (XRD) patterns, transmission
electron microscopy (TEM) photos and thermogravimetry/differential scanning calorimetry (TG–DSC)
property of the product without peptization were characterized and the results show that amorphous
particles with low crystallinity and poor thermal stability are obtained, and the effect of peptization
is to improve the properties, more accurately, regular particles with high crystallinity and good thermal
stability can be gained after peptization. Furthermore, the fundamental experimental parameters
including grinding time, the molar ratio of Mg to Al element (defined as R value) and the water content
were systematically examined in order to control the size and morphologies of LDHs particles, regular
hexagonal particles or the spherical nanostructures can be efficiently obtained and the particle sizes were
controlled in the range of 52–130 nm by carefully adjusting these parameters. At last, stunningly uniform
Mg–Al-LDHs particles can be synthesized under proper R values, suitable grinding time and high degree
of supersaturation.