Fast fabrication of highly regular and ordered ZrO2 nanotubes

This work reports a fast fabrication approach to attain highly regular and ordered zirconia (ZrO2) nanotubes with a narrow pore size distribution by electrochemically anodizing of a chemically etched Zr substrate in an ethylene glycol electrolyte containing small amounts of fluoride with a two-step process. The well-structured ZrO2 nanotubes grown in a very short period have an average diameter of 32.8 nm and a length of approximate 2.3 μm. The imprints on the Zr substrate after removal of the first-step anodized layer have ordered hexagonally packed pattern, which is crucial for the size uniformity and arrangement orderliness of ZrO2 nanotubes fabricated in the second anodization step.