Low temperature reduction route to synthesise bismuth telluride (Bi2Te3) nanoparticles: structural and optical studies

Herein, we report the synthesis of highly yielded bismuth-telluride (Bi₂Te₃) nanoparticles at 50 °C by direct wet chemical route in which the bismuth and tellurium precursors have been dissolved in deionised water, ethylene glycol and hydrazine hydrate. This method is very facile, inexpensive and less hazardous and ensures almost complete yield of the precursors. The powder product was well characterised by powder X-ray diffraction, UV-Vis spectroscopy, Fourier transform infrared spectroscopy, energy dispersive X-ray diffraction, transmission electron microscopy and scanning electron microscopy. It is investigated that the synthesised powder has a rhombohedral structure of Bi₂Te₃ with average diameters of the particles about 35 nm. Thus, the synthesis process has been modified to design nanostructures of thermoelectric materials with related crystal structures.