Polyol Synthesis of Nano-Bi2Te3

Abstract

In this work, a simple and easily scalable wet-chemical synthesis of nanoscale Bi2Te3 has been developed. Bi2Te3 nanoparticles were produced via a polyol method by reaction of Na2Te in solution with a selection of bismuth(III) salts in boiling ethylene glycol. Depending on the reaction temperature and time, particles with size ranging between 20 nm and 400 nm could be obtained in high yield. Phase-pure products could be obtained under refluxing conditions. We show the necessity of a certain reaction time or temperature for complete reaction of the compounds, and the dependence on the type of bismuth salt and the reactant quantity based on the tellurium contamination in the Bi2Te3 products. Nuclear magnetic resonance investigations suggest possible mechanisms for the formation of the Bi2Te3 particles. The composition, particle size, and morphology of the synthesized products were investigated by powder x-ray diffraction, energy-dispersive x-ray spectroscopy, transmission electron microscopy, and scanning electron microscopy. The resulting particles demonstrated high purity.