论文部分内容阅读
采用两种不同的溶剂热路径合成出了不同形貌和尺寸的CdS纳米晶,一种是以无水乙二胺(en)为溶剂,CdCl_2·2.5H_2O和硫脲(H_2NCSH_2N)为镉源和硫源,在不同反应温度(160℃—220℃下制备出了CdS纳米晶,讨论温度对CdS纳米晶生长的影响;另一种是以en为溶剂,将在160℃下合成的产物在200℃下原位再结晶生长2—8 h,分析原位生长时间对CdS纳米晶生长的影响.通过X射线衍射(XRD)、扫描电子电镜(SEM)和透射电子电镜(TEM)等表征产物的物相、形貌和微结构,分析可知:两种路线合成的产物均为六方相CdS;当温度为160℃时,产物形貌为纳米颗粒状,当温度高于160℃时,产物为CdS纳米棒状;同时,在200℃下原位再结晶生长不同时间后发现产物形貌由纳米颗粒转变为纳米棒,通过场发射扫描电镜(HRTEM)分析可知:纳米棒是由零维纳米颗粒自组装而成.最后,讨论了影响产物CdS纳米晶形貌转变的因素和纳米棒的生长机理.
Two kinds of CdS nanocrystals with different morphologies and sizes were synthesized by two different solvothermal routes. One was Cd (superscript 2 +) - H 2 O and H 2 NCSH 2 N Sulfur source, the CdS nanocrystals were prepared at different reaction temperatures (160 ℃ -220 ℃) to discuss the effect of temperature on the growth of CdS nanocrystals. The other method was to use en as solvent to synthesize the products synthesized at 160 ℃ The growth of CdS nanocrystals was analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) The phase, morphology and microstructure of the product were analyzed. The results showed that the products synthesized by the two routes were all hexagonal CdS. When the temperature was 160 ℃, the product morphology was nano-particle. When the temperature was higher than 160 ℃, the product was CdS Nanorods. At the same time, the morphologies of the products were changed from nanoparticles to nanorods by in-situ recrystallization growth at 200 ℃. The results of field emission scanning electron microscopy (HRTEM) showed that nanorods were self-assembled by zero-dimensional nanoparticles Finally, the factors that affect the transformation of CdS nanocrystals and nanostructures were discussed The growth mechanism.