Question

Describe the anodizing for the nanowire fabrication. How can you control the dimensions of nanowires?

Answer 1

The fabrication of metal nanowires has attracted considerable interest owing to their unique characteristics such as a large surface area, anisotropic electronic conduction, and so on. In particular, the fabrication of Al nanowires is desirable for their application as a material in energy conversion devices such as batteries, capacitors, and also to removal of condensed water.

To fabricate a one-dimensional nanostructure of porous anodic alumina oxide(AAO), anoidization process is used.

The growth of alumina oxide nanowires is observed via the anodization of aluminium on a silicon substrate in dilute sulphuric acid.

Anodization is performed using a two-step scheme in which the aluminum foil undergoes anodization and subsequent removal of its outer oxide layer leaving a nanoimprinted metal surface. The second anodization step facilitates the self-organized growth of regular and ordered pores in the alumina oxide layer, which results in better Porous anodic alumina oxide(AAO).

A scanning electron microscopy (SEM) study of the samples after the second oxidization step is employed to characterize the nanowires.

The anodization process generates nanowires with fine porous alumina layers with controlled geometrical structures.

The diameter of the nanoholes of the anodic porous alumina were controlled by changing the conditions of anodization i.e. anodization time and applying voltage.