Temperature-controlled growth of α-Al2O3 nanobelts and nanosheets

Alpha-Al2O3 nanobelts and nanosheets with different morphologies and sizes were successfully synthesised by a simple chemical route from H2O and Al in an Ar atmosphere. SEM and TEM observations show that the as-synthesised alpha-Al2O3 nanostructures consist of nanobelts and nanosheets. 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+ centres in the alpha-Al2O3 nanostructures. The growth of these products is believed to be mainly determined by growth kinetics as well as thermodynamics. 30 refs.