Calcinations of aluminum hydroxide (gibbsite) leads to a series of phase transitions. These phase transitions affect the
properties and activity of the resulting aluminum oxide. During this work, aluminum oxide nanoparticles were prepared by coprecipitation method with calcination of the resulting aluminum hydroxide at two different temperatures (600°C and 1000°C).
The structural properties of the resulting aluminum oxides were investigated using X-ray diffraction, Fourier Transform infrared
analysis, and Field Emission Scanning Electron Microscopy. The results indicate the formation of the amorphous γ -AlOOH and
γ- Al2O3 phases upon calcination of aluminum hydroxide at 600°C, while the γ-Al2O3 and α-Al2O3 phases are formed at
calcination at 1000°C. Also, a change in the shape and size of the formed crystals was observed with the increase in temperature.
The efficiency of the prepared oxides at different temperatures was compared in removing the reactive blue 4 dye by adsorption
method from the aqueous solution and it was found that amorphous aluminum oxide is more effective in removing the polluting
dye
Key words: Aluminum oxides nanoparticles, Phase transition,Calcination temperature , Adsorption
|
