Formation of zinc aluminum mixed metal oxide nanostructures

We report a method for synthesizing zinc aluminum layered double hydroxide (ZnAl:LDH) nanostructures at room temperature. The ZnAl:LDH nanoplates could be converted into zinc aluminum mixed metal oxide (MMO) nanostructures by calcination in air. The crystalline nature and morphology of the MMO nanostructures could be tuned by varying the calcination temperature. At low calcination temperatures (450–650 °C), nanostructures were composed of crystalline ZnO regions and amorphous regions. The crystalline orientations of the ZnO crystal grains were almost identical throughout the nanostructure. At calcination temperatures above 750 °C, ZnAl2O4 crystal grains appeared and amorphous regions could not be found in MMO nanostructures. As the calcination temperature increased, the crystal grain size and surface roughness of MMO nanostructures increased. Calcination at 950 °C resulted in the formation of MMO nanoparticles. The optical properties of the MMO nanostructures were probed by UV–vis diffuse reflectance spectroscopy. The spectra varied depending on their dimensions and crystalline natures.

We report a simple method for synthesizing zinc aluminum layered double hydroxide (ZnAl:LDH) nanostructures at room temperature and converting them into zinc aluminum mixed metal oxide (MMO) nanostructures by calcination in air. The crystalline nature and morphology of the MMO nanostructures could be tuned simply by varying calcination temperatures.Figure optionsDownload as PowerPoint slideHighlights
► Zinc aluminum layered double hydroxides (ZnAl:LDHs) were synthesized at room temperature.
► The ZnAl:LDHs were converted into zinc aluminum mixed metal oxide (MMO) by calcinations.
► Crystalline nature and morphology of the MMO could be tuned by varying calcination temperatures.
► Their optical properties varied depending on dimensions and crystalline natures.