Characterization of Bi2S3 nanorods prepared at room temperature

Bi2S3 is a direct band gap semiconductor with a band gap of 1.3eV. It belongs to the family of metal chalcogenides of type A2VB3VI (A=As, Sb, and Bi; B=S, Se, and Te), whose importance in photovoltaic and thermoelectric applications is well recognized. Although nanostructures of Bi2S3 have been obtained using a number of techniques, reports on assemblies of Bi2S3 are sparse. In the present work, we prepared single crystalline bismuth sulfide (Bi2S3) nanorods at room temperature by reacting Bi(NO3)3, thioacetamide (TAA), hydrochloric acid and distilled water. Energy dispersive analysis of X-rays (EDAX) obtained from Bi2S3 nanorods indicated no incorporation of other foreign impurities in it. X-ray diffraction confirmed the single phase of Bi2S3 and different diffracting planes were indexed based on the orthorhombic structure and lattice parameters were determined. X-ray photoelectron spectroscopy (XPS) was used to evaluate its composition and purity. The synthesized nanorods with different images observed under transmission electron microscopy (TEM) are shown in the paper and the selected area electron diffraction (SAED) pattern obtained from these nanorods shows their single crystalline behavior. Raman measurement performed at room temperature using Ar+ laser (488nm) confirms the presence of 238cm−1 and 972cm−1 phonon modes. The optical absorption spectra obtained by UV–vis spectrometer show blue shift in comparison to bulk Bi2S3 while its thermal stability was studied by thermogravimetric analysis.