Preparation of Bi2S3 nanorods via a hydrothermal approach

Large-scale bismuth sulfide (Bi2S3) nanorods with uniform size have been prepared by hydrothermal method using bismuth chloride (BiCl3) and sodium sulfide (Na2S·9H2O) as raw materials at 180 °C and pH = 1–2 for 12 h. The powder X-ray diffraction (XRD) pattern shows the Bi2S3 crystal belongs to the orthorhombic phase with calculated lattice constants a = 1.1187 nm, b = 1.1075 nm and c = 0.3976 nm. Furthermore, the quantification of X-ray photoelectron spectra (XPS) analysis peaks gives an atomic ratio of 1.9:3.0 for Bi:S. Field emission scanning electron microscopy (FE-SEM) and transmission electron microscopic (TEM) studies reveal that the appearance of the as-prepared Bi2S3 is rod-like with typical lengths in the range of 2–5 μm and diameters in the range of 10–30 nm. Finally the influences of the reaction conditions are discussed and a possible mechanism for the formation of Bi2S3 nanorods is proposed.