Growth behavior of tantalum oxide nanotubes during constant current anodization

Abstract

The standard method for growing tantalum oxide (Ta2O5) nanotubes is the constant voltage anodization mode. Although the constant current anodization mode is another feasible approach, the corresponding mechanism is not yet clear. In the present work, Ta2O5 nanotubes have been prepared by constant current anodization in an electrolyte containing HF. The results show that Ta2O5 nanotubes ~ 18 μm in length can be obtained with a very rapid growth rate within 2 min at a current density of 125 mA cm−2. In addition, the effects of current density, anodizing time, concentration of F− ions and electrolyte temperature on the morphology and growth rate of Ta2O5 nanotubes were studied. This work proposes an effective way of preparing tantalum oxide nanotubes under constant current anodic oxidation conditions, and paves the way toward large-scale production of Ta2O5 nanotubes.