L-胱氨酸辅助合成硫化铋纳米棒

以Bi(NO3)3·5H2O和L-胱氨酸为反应原料,分别以N,N-二甲基甲酰胺(N,N-dimethylformamide,DMF)、蒸馏水-乙二醇(体积比为2:1)和蒸馏水为溶剂,采用溶剂热法在160℃下反应120h,得到了不同形貌的硫化铋(Bi2S3)粉体。利用X射线衍射、能量色散谱、X射线光电能谱、场发射扫描电子显微镜和透射电子显微镜分别对所合成的Bi2S3的晶型结构、组成和表面形貌等进行了表征。结果表明:所合成的产物为典型的Bi2S3正交结构,在DMF溶剂中得到的Bi2S3纳米棒长为4～11μm,直径为120nm。在蒸馏水-乙二醇和蒸馏水溶剂中得到的是片状的Bi2S3晶粒。讨论了不同溶剂对Bi2S3的形成及其形貌的影响,并根据实验结果对所合成的一维纳米棒可能的形成机理进行了探讨。

L-CYSTINE-ASSISTED SYNTHESIS OF BISMUTH SULFIDE NANORODS

Nanostructured bismuth sulfide(Bi_2S_3) powder samples with different morphologies were synthesized by solvothermal method at 160℃ for 120 h using N, N-dimethylformamide (DMF), distilled water and distilled water-ethylene glycol (volume ratio 2:1) as the reaction solvent and Bi(NO_3)_3-5H_2O and L-cystine as the raw materials. The crystallinity, phase structure and morphology of the as-prepared samples were investigated by X-ray diffraction, energy dispersion spectroscopy, X-ray photoelectron spectroscopy, field-emission scanning electron microscopy and transmission electron microscopy. The results show the as-prepared Bi_2S_3 sample is typical Bi_2S_3 orthorhombic phase, and the diameters and lengths of nanorods of Bi_2S_3 synthesized in the DMF solvent are approximately 120 nm and 4-11μm, respectively. However, the Bi_2S_3 powder consists of nanoflakes when synthesis is carried out with distilled water and distilled water-ethylene glycol as the reaction solvent. The morphology and formation mechanism of Bi_2S_3 in different solvents are also discussed. A possible growth mechanism of one-dimensional nanorods is provided.