Aluminum nanowire arrays and methods of preparation and use thereof

1. A method for producing ordered metal nanowire arrays, comprising:

providing a metal substrate;

imprinting the surface of the metal substrate to form a plurality of indents and missing indents at lithographically-defined locations according to a pre-selected pattern;

anodizing the metal substrate to form a metal oxide template corresponding to the indents and missing indents; and

etching the anodized metal oxide to form a plurality of vertically-oriented and laterally-ordered metal nanowires according to the pre-selected pattern.

2. The method of claim 1 , further comprising rinsing the metal substrate.

3. The method of claim 2 , wherein the metal is aluminum (Al).

4. The method of claim 3 , wherein the metal substrate is a metal foil.

5. The method of claim 4 , wherein imprinting the surface of the metal substrate is performed with a Ni stamp.

6. The method of claim 5 , wherein anodizing the metal substrate forms a aluminim oxide (Al 2 O 3 ) template.

7. The method of claim 6 , wherein etching the anodized metal oxide results in a plurality of vertically-oriented, freestanding metal nanowires.

8. The method of claim 7 , wherein the plurality of vertically-oriented metal nanowires are laterally-ordered with discrete and controlled positions.

9. The method of claim 8 , wherein the plurality of vertically-oriented metal nanowires are characterised by a height being greater than about 10 μm and are positioned with pitches greater than about 2 μm.

10. The method of claim 9 , wherein the metal nanowires are characterised by a hexagonal cross-section comprising sharp edges.

11. The method of claim 4 , wherein imprinting the surface of the metal substrate is performed with a mask of Al 2 O 3 or SU8 and a PDMS stamp and etching imprints through openings in the mask before or during anodization.