Synthesis of Al-rich hydrotalcite-like compounds by using the urea hydrolysis reaction—control of size and morphology

Mono-dispersed sub-micron sized hydrotalcite-like compounds (HTlcs), [Mg1−xAlx(OH)2](CO3)y·2H2O, were synthesized by the urea hydrolysis method. The as-prepared compounds display platelet-like primary particles with a hexagonal shape. The breadth to thickness ratio can be varied by changing the synthesis conditions such as the precipitation rate or the medium nature. The factors influencing the secondary particle morphology (or aggregates) are also discussed. The results are compared to the constant pH coprecipitation method, commonly used for HTlcs.