Al₂O₃ Nanotubes Fabricated by Wet Etching of ZnO/Al₂O₃ Core/Shell Nanofibers

A route to fabricate Al₂O₃ nanotubes with conformally uniform thickness is discussed. ZnO/Al₂O₃ core/shell nanofibers are prepared from the Al₂O₃ deposition of ZnO nanowires with atomic-layer deposition (ALD). Amorphous Al₂O ₃ nanotubes with uniform thickness may be fabricated by wet-etching of the ZnO core nanowires in the ZnO/Al₂O₃ core/shell nanofibers in H₃PO₄ solution at 25°C. Straight-line and wave-shaped Al₂O₃ nanotubes with different inner diameters are fabricated by the method, depending on the morphology of ZnO nanowires used as templates.