As a whole: crystalline zinc aluminate nanotube array--nanonet.

A large-area crystalline zinc aluminate nanotube array on its own nanonet was prepared by thermal replication on an anodized aluminum oxide template and through the gas-solid reaction between Zn vapor, Al2O3, and residual O2 or produced H2O. The free-standing nanotube array plus the nanonet structure, as a whole, was at least 900 mum2 in area. Each nanotube, 70-80 nm in diameter, was seamlessly connected to an underlying pore in the nanonet and was about 800 and 15 nm in length and wall thickness, respectively. The nanonet was about 20 nm thick. Both the ZnAl2O4 nanotube and nanonet were in face-centered cubic crystal form and grew along the [12] direction.