Anodic Aluminum Oxide Template Assisted Synthesis of Copper Nanowires using a Galvanic Displacement Process for Electrochemical Denitrification

Metallic nanowires find widespread applicability, and a variety of synthesis techniques are available. Among these, template assisted deposition offers flexibility in terms of material and dimensional control. Here, we demonstrate a galvanic displacement process in combination with a nanoporous anodic aluminum oxide (AAO) template to fabricate copper nanowires. The AAO template was fabricated by anodizing aluminum in oxalic acid. Pore diameter and length could be readily controlled by adjusting the anodization parameters. Barrier layer thinning and chemical pore widening were then employed to open the pores at the bottom to expose the underlying aluminum metal. The synthesized AAO was used for the growth of copper nanowires by employing a chemical reduction reaction. This involved the dissolution of the aluminum metal and deposition of copper from the solution to form nanowires. The nanowires were then released from the template by etching and sonication and used as an electrode for electrochemical denitrification. The galvanic displacement demonstrated in this work offers a single step process for growing nanowires and can be readily adapted for a variety of metals and alloys using AAO.