Preparation of alumina nanowires, nanorods, and nanowalls by chemical etching

摘要

Alumina (Al_2O_3) nanowires, nanorods, and nanowalls have been prepared from anodic aluminum oxide (AAO) templates by chemical etching in NaOH solution. Heating the template prior to etching is crucial to the morphology of subsequent prepared alumina nanostructures, which greatly depend on the phases of the AAO templates. It has been found that the templates with amorphous Al_2O_3, γ-Al_2O_3, and α + γ-Al_2O_3 phases will grow nanowires, nanorods, and nanowalls, respectively. A possible mechanism for forming different alumina nanostructures is proposed.