Electrodeposition\nof Au Nanowires via Amine Ligand-Induced\nActive Surface Growth

Amine ligands have been widely applied as morphology-directing\nreagents in nanostructure synthesis. In this work, we explored the\napplication of the amine ligands in the active surface growth mechanism\nin place of the strong thiolated ligands. Despite being weaker compared\nto the thiols, amine ligands such as aniline were also shown to be\ncapable of facilitating the template-less electrodeposition of Au\nnanowires (NWs) on the substrate via the active surface growth mechanism.\nGiven the close binding difference between the amine-grafted substrate\nand the ligands, substrate functionalization becomes critically important\nfor effective construction of the active surface and the growth of\nthe nanowires. Additionally, the growth with the amine ligands took\nplace at more positive reduction potentials and is less prone to splitting\nand bundle formation. A systematic generality study revealed that\nbesides the aromatic amines, long-chain aliphatic amines were also\ncapable of facilitating nanowire growth. Given the weak binding affinity\nof the amine ligands, the Au NWs are readily accessible for further\nprocessing to generate sophisticated one-dimensional structures. As\na demonstration, tandem electrodeposition was performed to directly\nobtain coaxial core–shell Au@Pt NWs with adjustable length,\ndiameter, and shell thickness.