Sub-10 nm porous alumina templates to produce sub-10 nm nanowires

The versatility of Anodic Aluminum Oxide has led to the development of a variety of templates with ranging sizes, periodic modulations, and network-like architectures. These templates allow for the nanostructuration and study of new meta-materials, with interesting and important properties enhanced through size-reduction effects. In this work, we further extend the utility of these templates through the use of current anodization in concentrated Sulfuric acid and 25% V/V of ethanol under low current density values, obtaining small pore architectures with sub-10 nm features. In addition, polymer infiltration was performed as a proof of concept application, resulting in 8 nm nanowires. The templates reduced sizes allow for their application in the search for stable, extremely small diameter nanowires, and also for their use as scaffolds or filters.
M.M.G. acknowledges the financial support from the projects INFANTE 201550E072 and MAT2017-86450-c4-3-r. The authors acknowledge the service from the X‐SEM Laboratory at IMN, and funding from MINECO under project CSIC13‐4E‐1794 with support from EU (FEDER, FSE).