The synthesis of bismuth telluride nanowires with a high aspect ratio via precise regulation of growth rates

It is challenging to obtain one-dimensional nanowires with a high aspect ratio. Herein, we developed a controllable hydrothermal method to synthesize single-crystalline bismuth telluride (Bi2Te3) nanowires with a high aspect ratio. The effects of growth conditions including template, temperature, surfactant polyvinyl pyrrolidone (PVP) dosage, and pH value on the aspect ratio of Bi2Te3 nanowires were studied. The results show that Te nanowire templates not only support the epitaxial growth but also supply the Te source of Bi2Te3 nanowires. The reaction temperature, surfactant PVP, and pH were carried out to adjust the nucleation and diffusion rates of Bi and Te, thus controlling the growth rates of Bi2Te3 nanowires. The obtained Bi2Te3 nanowires have an aspect ratio of up to 100 (length of 7 µm and width of 70 nm).