Electrochemically controlled growth of Au-Pt alloy nanowires and nanodendrites

Abstract

The ability to control the morphology and phase structure of alloy nanowires is essential for the exploitation of their unique functional properties. This report describes the findings of an investigation of the growth mechanism in the electrochemically controlled growth of Au-Pt alloy nanostructures. By using a template-free alternating-current deposition method with different combinations of waveform, voltage, and frequency, controllability over the alloy morphology, composition, and phase structure has been clearly demonstrated for the growth of the nanostructures across the gap of two microelectrodes. The growth is proposed to involve an initial facet-selective nucleation-growth process followed by two competing nucleation-growth pathways that are highly tunable by the applied frequency and voltage. The findings provided new insights into the mechanism that underlies the controlled fabrication of alloy nanowires and nanodendrites with structurally tailorable functional properties.

Keywords: alloys; electrochemistry; gold; nanostructures; platinum.