One-step synthesis and size control of tin/indium (Sn/In) nanowires by surfactant-assisted chemical reduction methods in aqueous solutions

One dimensional tin/indium (Sn/In) nanowires have been synthesized through a surfactant assisted chemical reduction method in aqueous solutions at low temperature (∼0 °C). Synthetic parameters such as stirring speed, injection rate of reducing agent, and alloy ratio were used to control the size and aspect ratio of the resulting nanowires. It was observed that the diameter of the nanowires was around 70 nm for all the synthesis conditions that were studied, whereas the length of the nanowires can be controlled in the range of 400 nm to 2 μm. The morphology and structure of the Sn/In nanowires were characterized by field-emission scanning electron microscopy (FE-SEM), high-resolution transmission electron microscopy (HRTEM), and X-ray powder diffraction (XRD), and their thermal properties were measured by differential scanning calorimetry (DSC). Structure analysis indicated that the Sn/In nanowires were mainly composed of InSn₄ and Sn; whereas no In₃Sn phase was observed in the nanowires. DSC results confirmed the structures of the Sn/In nanowires that were measured through XRD and indicated that the nanowires started to melt at a relatively low temperature around 118 °C. Finally, a growth mechanism based on the reaction and structural evolution was proposed to explain the nanowire formation and growth process.