Preparation of mesoporous ZnAlO nanoflakes by ion exchange from a Na-dawsonite parent material in the presence of an ionic liquid.

Herein, mesoporous ZnAlO spinel nanoflakes were prepared by an ion-exchange method from a Na-dawsonite parent material in the presence of an ionic liquid, 1-butyl-2,3-dimethylimidazolium chloride ([bdmim][Cl]), followed by calcination at 700 °C for 2 h. The as-obtained products were characterized by several techniques such as X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy dispersive X-ray spectroscopy (EDX). The ZnAlO nanoflakes with the thickness of ∼20 nm were composed of numerous nanoparticles, which resulted in a high specific surface area of 245 m g. The formation mechanism of the ZnAlO nanoflakes was comprehensively investigated, and the results showed that a 2D growth process of the ZnAl(OH)(CO)·4HO crystallites with the assistance of [bdmim][Cl] was the key for the induction of ZnAlO nanoflakes. Moreover, mesopores were formed between adjacent nanoparticles due to the release of CO and HO molecules from ZnAl(OH)(CO)·4HO during the calcination process.