Indium telluride nanotubes: Solvothermal synthesis, growth mechanism, and properties

Abstract

A convenient solvothermal approach was applied for the first time to synthesize In2Te3 nanotubes. The morphology of the resultant nanotubes was studied by scanning electron microscopy and transmission electron microscopy. Nanotubes with a relatively uniform diameter of around 500nm, tube wall thickness of 50–100nm, and average length of tens of microns were obtained. X-ray diffraction, X-ray photoelectron spectroscopy, and Raman spectroscopy were used to study the crystal structures, composition, and optical properties of the products. To understand the growth mechanism of the In2Te3 nanotubes, we studied the influences of temperature, reaction time, and polyvinylpyrrolidone (PVP) and ethylene diamine (EDA) dosages on the final products. Based on the experimental results, a possible growth mechanism of In2Te3 nanotubes was proposed. In this mechanism, TeO3−2 is first reduced to allow nucleation. Circumferential edges of these nucleated molecules attract further deposition, and nanotubes finally grow rapidly along the c-axis and relatively slowly along the circumferential direction. The surface area of the products was determined by BET and found to be 137.85m2g−1. This large surface area indicates that the nanotubes may be suitable for gas sensing and hydrogen storage applications. The nanotubes also showed broad light detection ranging from 300nm to 1100nm, which covers the UV–visible–NIR regions. Such excellent optical properties indicate that In2Te3 nanotubes may enable significant advancements in new photodetection and photosensing applications.