Preparation of nanostructured microspheres of Zn–Mg–Al layered double hydroxides with high adsorption property

In this paper, hierarchical nano/micro-structured Zn–Mg–Al layered double hydroxides (ZnMgAl-LDHs) were successfully synthesized by a one-step urea-method. The morphology, structure, surface area, and adsorption properties of the prepared samples were characterized. The results show that the ZnMgAl-LDHs are of high crystallinity with large surface area, which is favorable for the adsorption. The optimum pH value for the adsorption of methyl orange onto the ZnMgAl-LDHs is 3.0. The adsorption process can be well described by the pseudo-second-order kinetic model. The adsorption isotherm of methyl orange onto the ZnMgAl-LDHs can be depicted by both Freundlich and Langmuir equations, but the latter model matches the results much better than the former one.