Synthesis and structural analysis of a regular Cu-Mg-Al hydrotalcite-like compound

A fine-quality, regular Cu-Mg-Al hydrotalcite-like compound was synthesized via the glycothermal method using CuCl_2·2H_2O, MgCl_2·6H_2 O, AlCl_3·6H_2O, and Na2CO_3 as raw materials and sodium hydroxide as the precipitant. Hydrotalcite samples were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, thermogravimetricdifferential thermal analysis, and Brunauer-Emmett-Teller N2 surface area measurements. The influence of glycol content on the characteristics of the sample was investigated. The results show that the glycol content in the system had a greater impact on regular hydrotalcite with an intercalated structure. A Cu-Mg-Al hydrotalcite-like compound with a well-defined shape, distinct intercalated structure, regular quality, and good dispersing capability could be obtained under the following conditions: glycol volume ratio of 10%, hydrothermal temperature of 180 ◦C, and reaction time of 15 h. The compound obtained was well crystallized and had the morphology of a homogeneous and hexagonal sheet. The thickness of each hexagon in the hydrotalcite was about 40 nm, which was consistent with the value estimated with the Scherer equation.