High aspect ratio, self-ordered iron oxide nanopores formed by anodization of Fe in ethylene glycol/NH4F electrolytes

In the present work we show that highly self‐ordered iron oxide nanopores can be anodically grown to high aspect ratios, in optimized fluoride‐containing ethylene glycol electrolytes. The as‐formed layers are amorphous and contain a significant amount of fluorides. By annealing the layers can be crystallized and the fluorides can be removed. At elevated electrolyte temperatures the nanoporous system shows a transition to a nanotubular structure. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) The Letter describes the formation of highly self‐ordered iron oxide nanopores by the anodization process of iron in fluoride‐containing ethylene glycol electrolytes. The as‐formed porous layers are amorphous and contain a significant amount of fluorides. By thermal annealing the fluorides can be removed from the structure and crystallized porous layers are obtained. At elevated electrolyte temperatures a transition of the nanoporous system to a nanotubular structure is observed.