CdS纳米棒的水热法制备及形成机理研究

采用水热法以Na2S· 9H2O为硫源,Cd3O12S3·8H2O为镉源,PVP为表面活性剂,成功制备了CdS纳米棒.并利用X射线衍射(XRD)、透射电子显微镜(TEM)和相应选区电子衍射(SAED)、高分辨透射电子显微镜(HRTEM)、X射线能量色散分析谱仪(XEDS)和紫外可见(UV-vis)分光光度计等测试手段对样品的晶体结构、形貌、微观结构和光学特性等特征进行了表征分析,实验结果表明本方法所制备的CdS纳米棒为纤锌矿结构,沿001]方向择优生长,平均直径大约为50 nm,棒宽均匀、分散性好,带隙为2.43 eV.同时也对CdS纳米棒的形成机理进行了初步探讨,提出了CdS纳米棒的生长模型,其形貌从三角形到阶梯形棒晶,最后再到完整的棒状晶体的一个定向团聚的自组装过程.

Synthesis and Formation Mechanisms of CdS Nanorods by Hydrothermal Method

CdS nanorods were successfully synthesized via hydrothermal method using cadmium sulfide and sodium sulfide as cadmium source and sulfur source respectively,and using polyvinylpyrrolidone as the surfactant.The crystal structure,morphology,microstructure and optical property of the products by this process were investigated via X-ray diffraction(XRD),transmission electron microscopy(TEM) and the corresponding electron diffraction(SAED),the high-resolution transmission electron microscopy(HRTEM),X-ray energy dispersive spectrometry(XEDS) and ultraviolet-visible spectrophotomete(UV-vis).The experiment results show that the sample is wurtzite structure and grows along the direction,the average diameter about 50 nm,the diameter of the samples are homogeneously distributed and well dispersed,the band gap is 2.43 eV.The formation mechanism was discussed about CdS nanorods,then the CdS nanorods formation model was proposed that it was a self-assembly and directed reunion process,which was from the triangle to the ladder,and finally to the complete nanorods crystals.