竹节状CNTs/CdS核壳纳米线的制备与形态特征

以竹节状碳纳米管(CNTs)为模板,采用常温化学还原路线制备了CNTs/CdS核壳纳米线,用透射电子显微镜(TEM)观察了产物的微观形貌,用X射线衍射(XRD)技术分析了产物的物相,证实所得产物由CNTs与六方格子的CdS纳米晶体构成,具有核壳纳米线结构.研究发现CNTs竹节状的形态特点影响了得到的核壳结构的纳米线的微观形貌.在反应物浓度较低时,CdS晶体不像在侧壁平直的CNTs表面生长那样均匀包覆在CNTs表面,而是呈现根瘤状形貌;当反应物浓度升高时,CdS晶体均匀包覆在CNTs表面.当把还原反应时间缩短(如15m in),观察到CNTs环绕在CdS纳米晶体表面的新形态,推测这与CNTs的竹节状特殊形态有关.这些结果对于阐明CNTs/化合物半导体复合材料的形态结构控制原理和开发新材料具有重要参考价值.

Core/Shell Nanostructure of Bamboo-Shaped Carbon Nanotubes and CdS Nanocrystalline: Preparation and Morphology

Carbon Nanotubes（CNTs）/CdS core-shell nanowires were prepared through a room-temperature chemical reduction method by using bamboo-shaped CNTs as template.The morphology and the phases of the resultants were characterized with transmittance electron microscope（TEM） and X ray diffraction（XRD） techniques,respectively.It was confirmed that the resultants were composed of CNTs and hexagonal lattice CdS nanocrystals,and exhibited a typical morphology of core-shell nanowire.In low reactant concentration,different from commonly observed for uniform coating of CdS component on CNTs with smooth-surface,nodule-like deposition of CdS nanocrystals on CNTs＇ surface was observed;and uniform coating was only observed at higher reactant concentration.As the reaction time was shortened（e.g.15 minutes）,a unique morphology was found that the bamboo-shaped CNTs circled around CdS nanoparticles.Such a novel nanostructure was tentatively associated with the bamboo-shape of the CNTs component.The present results can help to get more understanding of the morphology and structure tuning of CNTs/semiconductor nanocrystalllines composites.