Abstract

Composite materials that contain tetracationic hydrotalcite-like layered double hydroxide and a cobalt-iron spinel phase were prepared by coprecipitation from a solution of a mixture of magnesium, aluminum, cobalt(II), and iron(III) salts followed by hydrothermal treatment. The iron and cobalt contents in the samples were varied within a broad range. The thermal transformations of the prepared composites were examined by high-temperature X-ray diffraction, and the layered hydroxide phase was found to remain when heated up to 300°C. The specific magnetization and magnetic susceptibility of the materials were determined using a vibrating sample magnetometer; a rise in the iron and cobalt contents was found to increase the magnetization up to a certain limit. The obtained samples can be used as magnetic sorbents. The sorption capacity of materials was estimated using Congo red anionic dye as an example.