Abstract: Alumina nanorods were successfully prepared from the thermal decomposition of Al(OH)₃·xH₂O nano precursors obtained hydrothermally at 120℃ for 10--17d, by using Al(OH)₃ and LiOH as raw materials. The as-prepared samples were characterized by TEM, HRTEM, SAED and XRD. Besides, the thermal behavior of decomposing Al(OH)₃·xH₂O precursors synthesized by hydrothermal process was studied through TGA. The results show that the as-prepared Al₂O₃ nanorods have rod-like morphology and single crystalline nature. The mechanism for the Al₂O₃ nanorods growth is agreed to Ostwald ripening and oriented attachment. Lye plays an important role in synthesizing the Al₂O₃ nanorods. As 5mol/L KOH lye displaces original LiOH, the
as-prepared nanowires in the reaction have smaller morphology, with a diameter of 2nm and a length of 10--25nm.

Key words: Al₂O₃, nanorods, hydrothermal synthesis, thermal decomposition