Controllable synthesis of Bi 2S 3 hierarchical nanostructures: Effect of addition method on structures

Abstract

Bi 2S 3 microcrystallites with three-dimensional (3D) superstructures were synthesized by the reaction of bismuth nitrate (Bi(NO 3) 3) with sodium O-isopropyldithiocarbonate (isopropyl xanthate, C 3H 7OCS 2Na) at 80 °C in N, N-dimethylformamide (DMF) solution without any surfactants. It was observed that Bi 2S 3 crystalline nanorods aggregated to urchin-like globules in the microscale when C 3H 7OCS 2Na was slowly added to Bi(NO 3) 3 in DMF solution at 80 °C, while cockscomb-like microspheres aggregated by Bi 2S 3 nanobelts with a typical width of ∼20 nm were obtained if two precursors were mixed at room temperature and then heated to 80 °C. Possible mechanisms for the formation of 3D Bi 2S 3 microcrystals were proposed. The structures of Bi 2S 3 crystals were examined by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and laser Raman spectroscopy.