Temperature-controlled growth of α-Al2O3 nanobelts and nanosheets

alpha-Al2O3 Nanobelts and nanosheets with different morphologies and sizes have been successfully synthesized by a simple chemical route from H2O and Al in an argon atmosphere. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) observations show that the as-synthesized alpha-Al2O3 nanostructures consist of nanobelts and nanosheets. We find that the temperature distribution inside the alumina tube is the critical factor determining the morphologies and sizes of the alpha-Al2O3 nanostructures. Photoluminescence measurements showed a blue luminescence band in the wavelength range of 400-500 nm, which can be attributed to F+ centers in the alpha-Al2O3 nanostructures. The growth of these products is believed to be mainly determined by growth kinetics as well as thermodynamics.