Synthesis of novel mesoporous Al2O3 microspheres with flower-like structure

Using glucose as a structuring additive and aluminium nitrate as the Al precursor, a novel kind of mesoporous Al₂O₃ microspheres with flower-like structure were synthesized hydrothermally at 180°C for 20 h. When the synthesis temperature was lowered to 140°C, the carambola-like Al₂O₃ can be synthesized. This approach is convenient and simple, and flower-like Ce-Al₂O₃ and La-Al₂O₃ spheres have also been prepared in this way. It may be applied to synthesize other metal oxides when suitable precursor salts are used. From an analysis of the experimental results, a mechanism for the formation of the flower-like Al₂O₃ spheres has been proposed and discussed.