有序CdS纳米线阵列的制备和光学特性

应用直流电沉积法在多孔氧化铝模板中制备了高度有序的CdS纳米线阵列,并由XRD、Raman、SEM、TEM和HRTEM等进行物理化学表征.结果表明,沉积在多孔氧化铝模板中的CdS呈六角结构,c轴沿孔长度方向定向生长.紫外吸收光谱研究表明,随着纳米线尺寸的减小,纳米线阵列的吸收边向短波长方向移动,荧光光谱测量显示,CdS纳米线阵列的荧光强度高于氧化铝模板,而且在可见光区的荧光特性与激发波长无关.     

一种新的电化学方法制备CdS纳米线阵列

用一种新的电化学方法在多孔氧化铝模板中制备了CdS纳米线阵列体系,并用XRD、TEM对样品进行表征,结果显示CdS纳米线为立方相和六方相的多晶混合结构,对沉积机理进行了讨论.荧光光谱测量显示CdS纳米线阵列体系有三个强的紫外发光带和一个黄绿发光带.该文所使用的方法可以用来在氧化铝模板中制备其它材料的纳米线阵列体系.     

利用拉曼和表面光电压谱对一维TiO2@CdS核壳结构界面电荷行为研究

利用化学气相沉积法制备了直径约90 nm,长数十微米的高质量TiO2纳米线.通过化学浴沉积法(CBD)在纳米线表面生长CdS包覆层,形成了一维TiO2@CdS核壳结构.不同包覆层厚度的一维TiO2@CdS核壳结构拉曼光谱研究发现TiO2/CdS界面的光生电荷转移对CdS和TiO2拉曼响应均有增强效应.结合表面光电压谱研究发现表面包覆层的厚度对TiO2/CdS界面光生电荷转移有显著的影响.表面CdS包覆层厚度对拉曼和表面光伏响应影响的研究表明电子在CdS包覆层中的电子扩散距离在30～60 nm.     

利用牛血清蛋白合成CdS纳米棒和网状纳米线

采用简单易控、对环境友好的矿化方法, 利用牛血清蛋白(BSA)做模板, 通过Cd2+与硫代乙酰胺(TAA)反应制备了形貌均一的CdS纳米棒和网状纳米线. 分别采用透射电子显微镜(TEM)、X射线能谱(EDS)、X射线衍射(XRD)、荧光(PL)发射谱和导电原子力显微镜(C-AFM)等方法对不同实验温度下制备的CdS样品的结构形貌、成分组成和光学性质及微区电子传输行为进行了表征. 结果表明: 在实验反应温度为20 ℃时, 得到的产物为单分散性好的CdS 纳米棒, 长度为250 nm, 直径为30 nm; 在50 ℃时, 得到网状CdS纳米线, 其长度为2-3 μm; CdS纳米棒和网状纳米线均为立方相闪锌矿结构. 荧光性质的测试表明, CdS纳米棒和网状纳米线具有优良的荧光性能, 电流-电压(I-V)特性的表征表明CdS纳米线具有很好的电导特性.     

模板法制备硫化物半导体纳米材料

本文以聚氧乙烯类表面活性剂AEO-7形成的六方相液晶为模板分别制备出了CdS 和ZnS 纳米线及中孔结构的CdS及PbS;以阳极氧化铝位模板制备除了一系列硫化物半导体纳米线阵列。     

Zn_xCd_(1-x)S纳米线的可控合成及其可调的光学性质（英文）

采用简单的气相沉积法,合成了不同组成的Znx Cd1-x S(0x1)纳米线.利用扫描电子显微镜、透射电子显微镜和电子能谱研究了所制得的纳米线的表面形貌和组成.该方法以Au为催化剂,简单控制起始物质的相对用量和沉积温度,可以获得可控的Zn/Cd比例.X射线衍射结果表明所制得的Znx Cd1-x S纳米线具有纤维锌矿的单晶结构.根据制得纳米线的表面形貌讨论了纳米线可能的生长机理为"底部生长"机理.利用拉曼光谱和光致发光光谱研究了Znx Cd1-x S纳米线的光学性质,其纵向光学(LO)声子的拉曼位移频率随着组成的变化在ZnS和CdS的拉曼位移频率之间连续变化.光致发光光谱中同时存在带边发光和缺陷发光.Znx Cd1-x S纳米线的带间跃迁的频率可随着组成的调节而调节,纳米线的禁带宽度介于ZnS(3.63 eV)和CdS(2.41 eV)的禁带宽度之间.     

生物模板法常温合成CdS纳米线

采用新型生物模板法常温合成CdS纳米线的新方法,并对其结构和性能进行了表征。SAED分析表明:生物模板表面包覆上了结晶良好的CdS纳米颗粒。TEM照片表明:CdS纳米线长(4±0.6)μm,直径为(400±55)nm,构成纳米线的CdS颗粒尺寸为(5.5±0.3)nm。荧光光谱分析表明:该纳米线具有优异的荧光性质,使其在生物,电子领域有潜在的应用。     

硫化镉纳米线的电沉积制备及表征

以不同孔径的多孔阳极氧化铝为模板,采用直流电沉积的方法,在含CdCl2和S的DMSO溶液中制备出了CdS纳米线．SEM、TEM表征的结果表明,在不同孔径的多孔阳极氧化铝模板中,通过沉积时间等条件的控制,制得直径不同、长度可达5μm的平行结构、均匀而连续的CdS纳米线阵列．电子衍射和能谱结果显示所得的纳米线属于六方晶系CdS,线中Cd和S原子比接近1：1．     

GaSb纳米线的CVD可控制备及其光学表征

采用CVD法合成GaSb纳米线,并分析生长时间对其长度的影响,随后对其进行光学表征.实验过程中,分别采用喷金法和滴金法对硅片进行预处理,再置于相同条件下制备GaSb纳米线;之后对其进行表征分析,根据扫描电子显微镜（SEM）表征结果证实,两种方法制备的纳米线都满足VLS生长机制.且发现GaSb纳米线的生长长度,可以通过改变其生长时间来进行控制.通过该纳米线的透射电子显微镜图（TEM）、X射线衍射图（XRD）等结构表征,表明该纳米线为结晶品质优良的立方闪锌矿结构;同时,从GaSb纳米线的拉曼光谱（Raman）及光致发光谱（PL）可以反映该纳米线具有优良的光学性质.由此证明,采用CVD法制得的纳米线光学性质优异,且可以实现可控制备.     

液晶模板法合CdS纳米线(英文)

以六方液晶为模板合成了CdS纳米线。纳米线生长在表面活性剂分子形成的六方堆积的空隙水相内，呈平行排布，直径为1-5nm。     

Solvothermal synthesis and characterization of uniform CdS nanowires in high yield

Large-scale CdS nanowires with uniform diameter and high aspect ratios were synthesized using a simple solvothermal route that employed CdCl₂ and S powder as starting materials, ethylenediamine (en) as the solvent. X-ray diffraction (XRD) pattern and transmission electron microscopy (TEM) images show that the products are hexagonal structure CdS nanowires with diameter of 40 nm and length up to 10 μm. Selected area electron diffraction (SAED) and high resolution TEM (HRTEM) studies indicate the single-crystalline nature of CdS nanowires with an oriented growth along the c-axis direction. The optical properties of the products were characterized by optical absorption spectra and photoluminescence spectra. Based on the results of contrastive experiments, it is found that the sulfur source and the solvent play significant roles in the formation of uniform nanowires. A possible formation mechanism of nanowires is discussed.     

CdS和CdSe新型纳米结构的高效溶剂热合成

采用快速高效的溶剂热法合成了海星形CdS纳米结构和一维CdSe纳米结构。用XRD、SEM和UV-Vis等表征手段对产物进行了表征，结果表明产物为单一的CdS和CdSe纳米结构，且CdS纳米结构具有良好的分散性，其形成极大地受到pH值影响，而CdSe先形成层状的二维结构、再形成一维纳米结构。     

Sacrificial template growth of CdS nanotubes from Cd(OH)2 nanowires

A diffusion-controlled process was proposed for the preparation of inorganic nanotubes from nanowires. The preformed Cd(OH)₂ nanowires were used as the sacrificial templates to generate CdS nanotubes with different wall thickness. The axle-sleeve transition state found in-between the precursor and the formation of products proves the diffusion-controlled mechanism. CdS nanotubes can be prepared via this method at different temperature and with various sulfide sources. X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM) results showed that all obtained CdS nanotubes consist conglomerated crystallites, and the crystallinity can be altered by changing the temperature of the growth process. The wall thickness of the produced CdS nanotubes can be controlled by changing the concentration of the sulfide source and stopping the reaction at different stages.     

Solvothermal synthesis of CdS nanowires in a mixed solvent of ethylenediamine and dodecanethiol

CdS nanowires with an average diameter of 25 nm and lengths of 20-40 mum have been solvothermally synthesized in a mixed solvent of ethylenediamine and dodecanethiol at 180 degrees C. The time-dependent examinations reveal that the formation process of CdS nanowires involves two sequential processes: a short-period solid-solid transformation process in the initial stage and a long-period Ostwald ripening process. The effect of both the volume ratios between the two components of the solvent and the reaction temperatures on the nanowire growth has also been investigated in detail. The results of the photoluminescence and UV-vis spectroscopy measurements reveal that the as-prepared CdS nanowires show a quantum confinement effect.     

Growth of long CdS nanowires using a carboxylic acid-functionalized self-assembled monolayer as substrate

We report a novel result that long CdS nanowires with typical width of 70–80 nm and length ranging from several micrometers to tens of micrometers can be obtained by the in situ growth on substrate of a carboxylic acid-functionalized self-assembled monolayer (SAM), which formed from a rigid aromatic molecule on mica surfaces. The as-grown CdS nanowires were characterized by X-ray photoelectron spectroscopy (XPS), Transmission electron microscopy (TEM) and Energy-dispersive X-ray spectroscopy (EDS). A possible mechanism that accounts for the formation of the one-dimensional (1D) nanowires was also discussed.     

Synthesis of uniform CdS nanowires in high yield and its single nanowire electrical property

Large-scale high quality CdS nanowires with uniform diameter were synthesized by using a rapid and simple solvothermal route. Field emission scan electron microscopy (FESEM) and transmission electron microscopy (TEM) images show that the CdS nanowires have diameter of about 26 nm and length up to several micrometres. High resolution TEM (HRTEM) study indicates the single-crystalline nature of CdS nanowires with an oriented growth along the c-axis direction. The optical properties of the products were characterized by UV-vis absorption spectra, photoluminescence spectra and Raman spectra. The resistivity, electron concentration and electron mobility of single NW are calculated by fitting the symmetric I-V curves measured on single NW by the metal-semiconductor-metal model based on thermionic field emission theory.     

Architectural control syntheses of CdS and CdSe nanoflowers, branched nanowires, and nanotrees via a solvothermal approach in a mixed solution and their photocatalytic property

Wurtzite CdS and CdSe nanostructures with complex morphologies such as urchin-like CdS nanoflowers, branched nanowires, and fractal nanotrees can be produced via a facile solvothermal approach in a mixed solution made of diethylenetriamine (DETA) and deionized water (DIW). The morphologies of CdS and CdSe nanocrystals can be easily controlled via tuning the volume ratio of DETA and DIW. Urchin-like CdS nanoflowers made of CdS nanorods are in a form of highly ordered hierarchical structures, while the nanowires are branched nanowires, and the fractal CdS nanotrees are a buildup of branched nanopines. The results demonstrated that solvothermal reaction in a mixed amine/water can access a variety of complex morphologies of semiconductor materials. The photocatalytic activity of CdS particles with different morphologies has been tested by the degradation of acid fuchsine under both UV and visible light, showing that the as-prepared branched CdS nanowires exhibit high photocatalytic activity for degradation of acid fuchsine.     

Rapid elongation of CdS nanowire at room temperature

The CdS nanowires synthesized by solvothermal route are rapidly elongated in the presence of the ethylenediamine by ultrosonication method at room temperature. Transmission electron microscopy (TEM) analysis reveals that the influential factors on the rapid elongate process are the concentration of ethylenediamine and duration of the ultrosonication reaction. The elongated CdS nanowires are further characterized by UV–vis absorption spectra, which has no apparent difference in the position of the maximum absorption peak comparing with the starting CdS nanowires synthesized by solvothermal method. A mechanism of oriented attachment is proposed to explain the phenomena based on a series of experimental results.     

片状碘化铋辅助液相法合成硫化镉纳米线的取向行为和场发射特性

利用低温液相法可控合成有序硫化镉纳米结构. 用片状碘化铋作为可分解的二维模板实现硫化镉纳米线的生长调控. 采用不同尺寸的片状碘化铋并控制反应温度, 成功制备出硫化镉纳米线的平面方形网状结构、无序交织网状结构和有序阵列结构. 电子显微分析、X射线衍射和光致发光分析显示, 这些纳米结构晶化程度良好. 场发射测试表明, 硫化镉纳米线由横向排列向竖直排列的可控变化使得硫化镉纳米线平面方形网状结构、无序交织网状结构和有序阵列结构的场发射性能依次增强.