Facile route for preparation of highly crystalline γ-Al2O3 nanopowder

In this study, the sol-gel technique has been used to synthesize highly crystalline gamma-alumina. Aluminum chloride, ethanol, and water were selected for sol-gel process and a facile route has been developed to prepare the nanocrystalline gamma-aluminum hydroxide (gibbsite). FTIR and X-ray diffraction were used to identify the organic compounds of prepared sol and the crystallographic phase of synthesized powders. Scanning electron microscopy (SEM) studies were carried out to show the morphology of prepared powders. The phase transformation from gibbsite to gamma-alumina has been evaluated by annealing of the prepared sample at different temperatures. The aging process has highly affected the degree of crystallinity of gamma-alumina. Experimental results confirmed that the phase transformation from gibbsite to gamma-alumina has been started at low temperature (200 C) and highly crystalline gamma-alumina was obtained at 1000 degrees C. (C) 2011 Elsevier B.V. All rights reserved.