Enhanced anodization growth of self-organized ZrO2 nanotubes on nanostructured zirconium

► The growth of ZrO2 nanotubes can be enhanced on nanocrystallized Zr. ► Grain boundaries play the leading role in enhancing the reaction rate during anodization. ► Nanocrystallization of Zr enhances the crystallinity of ZrO2 nanotubes at top-end.