Synthesis of bismuth sulfide nanorods by microwave irradiation

Bismuth sulfide nanorods were synthesized from bismuth citrate and thiourea by microwave irradiation in the presence of surfactants. The products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The influence of surfactants on the morphology and crystallization of Bi₂S₃ nanorods was discussed. It is found that cetyltrimethyl ammonium bromide (CTAB) and β-cyclodextrin (β-CD) benefit the formation of Bi₂S₃ nanorods. Low concentration of β-CD (~0.005 mol·L^-1) is favorable to the synthesis of well-separated Bi₂S₃ nanorods. The effect of preparation methods on the synthesis of Bi₂S₃ nanorods was also discussed. The results show that microwave irradiation saves about 80% of reaction time in comparison with the refluxing method, and Bi₂S₃ nanorods exhibit different crystal lattice growth directions in these two methods.