Rapid preparation of nano hexagonal-shaped hydrocalumite via one-pot mechanochemistry method

Hexagonal-shaped hydrocalumite (Ca-Al layered double hydroxides) was successfully synthesized by one-step mechanochemistry method within only 30 min. The product was characterized by X-ray diffraction, Fourier Transform Infrared spectroscopy, field emission scanning electron microscopy, energy dispersive spectroscopy, elemental mapping analysis, transmission electron microscopy, X-ray fluorescence, and thermogravimetric analysis. The results showed that the formation of a well-defined hydrocalumite and the microstructural evolution were strongly dependent on the milling time. From XRD profiles, a well-crystallized hydrocalumite with higher peaks intensity was formed after 60 min of milling, while the sharpness and intensity of LDH-derived XRD peaks decreased as milling time increased. Microscopic analysis showed that the product had hexagonal layered structure with lateral dimension of 100 to 200 nm. In addition, the thermal decomposition of the product is reported in details. This study offers a low-cost approach to synthesis of hydrocalumite owing to simplicity and extremely short processing time.