Synthesis of zinc oxide nanotubes within ultrathin anodic aluminum oxide membrane by sol–gel method

In this paper we report a simple method that enables the easy fabrication of ultrathin porous anodic aluminum oxide (AAO) membranes from two-step anodization in oxalic acid solution. ZnO nanotubes have been synthesized by injecting sol–gel into the pores of the ultrathin AAO membrane. The structures and morphologies of the ultrathin AAO membrane and ZnO nanotubes were characterized by X-ray diffraction, scanning electron microscopy and transmission electron microscope. The thickness of the as-prepared AAO membranes is about 1 μm with highly ordered pores inside, and the ZnO nanotubes are straight with uniform thickness along the length and with diameter equal to those of nanopores.

► Ordered ZnO nanotubes have been prepared by sol-gel method into ultrathin AAO membrane.
► Integrating ultrathin AAO with sol-gel technique helps to fabricate nanomaterials.
► This method may extend the AAO application as template for nanostructures growth.