Enhanced self‐ordering of anodic ZrO 2 nanotubes in inorganic and organic electrolytes using two‐step anodization

This work reports on the optimized growth of self‐ordered ZrO 2 nanotubes in inorganic water‐based and organic electrolyte systems containing small amounts of fluoride employing a two‐step anodization process. We show how surface pretreatments of the metallic Zr substrate can drastically improve the growth and morphology of the resulting anodic ZrO 2 nanotube arrays. Using two step anodization and employing organic electrolytes, highly regular and ordered nanotubular ZrO 2 oxide layers can be grown to significantly increased tube lengths compared with aqueous electrolytes. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)