High aspect ratio ordered nanoporous Ta2O5 films by anodization of Ta

In this work we report the electrochemical formation of self-organized high aspect ratio Ta2O5 porous layers, grown by anodization of Ta in non-aqueous electrolytes consisting of glycerol and small additions of NH4F. Under optimized electrochemical conditions in these glycerol based electrolytes, the porous layers can be grown up to thickness of 15 μm, with a pore diameter in the range of 10–40 nm. The dimensions and the morphology of the layers can be strongly influenced by the fluoride concentration, the applied potential and the water content in the electrolyte.