Aging time effect on the formation of alumina nanowires on AAO templates

Abstract

This article presents the fabrication of alumina nanowires by etching AAO templates using chromic acid solutions. Our work has shown that an aging process in the ambient atmosphere for a relatively long time is indispensable to obtain uniform, small diameter alumina nanowires, which may be due to the release/redistribution of internal stresses of AAO template. The study of the formation mechanism leads to the optimization of the fabrication procedure. Alumina nanowires with a diameter of 5-10 nm have been achieved with a very good uniformity, an excellent surface coverage, and a relatively large BET surface of 50 m2/g.