共查询到19条相似文献,搜索用时 234 毫秒
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MS(M=Cd或Zn)纳米粒子负载TiO_2纳米线的制备及可见光催化性能 总被引:3,自引:0,他引:3
以具有层状结构的钛酸盐纳米线、CdCl2或ZnSO4及硫代乙酰胺为原料,采用两步水热合成法制备了高温稳定的六方相CdS或低温稳定的立方相ZnS纳米粒子负载的TiO2纳米线复合材料。首先,CdCl2或ZnSO4与钛酸盐纳米线在水热条件下进行离子交换制得含Cd2+或Zn2+的钛酸盐纳米线;然后,在硫代乙酰胺溶液中于160℃下直接处理含Cd2+或Zn2+的钛酸盐纳米线就可获得负载有硫化物纳米粒子的TiO2复合纳米线。它们在酸浸后,TiO2纳米线的表面仍存在少量硫化物纳米粒子。通过测试酸浸后样品、纯TiO2纳米线和商用P25对亚甲基蓝水溶液的可见光催化降解实验结果证实,含CdS纳米粒子样品的光催化活性最高。 相似文献
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以氧化镉为镉源、硫单质为硫源、油酸为配体、在十八烯体系中合成单分散的CdS纳米颗粒,研究了配体浓度对纳米微粒的生长动力学、颗粒尺寸分布的影响.采用乙基黄原酸锌作为Zn、S源的反应前体,采用逐滴滴加的方法制备了具有核壳结构的CdS/ZnS量子点,吸收光谱和荧光光谱表明CdS/ZnS纳米粒子比单一的CdS纳米粒子具有更优异的发光特性.透射电子显微镜、X射线粉末衍射、X射线光电子能谱、选区电子衍射证明ZnS在CdS表面进行了有效包覆.所制备核壳结构纳米粒子具有较好的尺寸分布,荧光发射峰半高峰宽为18~20nm,荧光量子产率达40%. 相似文献
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概述了脂类、蛋白质、DNA等生物分子模板表面化学沉积制备低维金属纳米材料的最新研究进展.脂类、蛋白质和DNA分子可自组装形成不同的纳米结构,如纳米管和纳米线等.这些不同的纳米结构可作为模板,化学沉积制备不同的低维金属纳米材料.金属纳米管具有高强度、导电、导热、磁性,在电活性复合材料,药物和海洋防污剂的可控缓释等领域有重要的应用;金属一维纳米线具有特殊的量子效应,可用于纳米器件和纳米电路的开发.该研究可以帮助人们将生物学知识转变为材料学知识,该方法是分子自组装纳米材料和纳米结构走向工程应用的重要途径之一. 相似文献
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在非配位溶剂中合成了高质量的CdS纳米晶核,并利用Cu2+离子对其进行掺杂,制备了CdS∶Cu纳米晶.通过进一步采用连续离子层吸附反应的方法对CdS∶Cu纳米晶进行表面修饰,得到CdS∶Cu/CdS复合结构纳米晶.利用X射线衍射(XRD),透射电镜(TEM),紫外可见吸收光谱(UV-Vis)和荧光光谱(PL)对其结构、形貌以及光学性质进行了表征和分析,结果表明:所制备的复合结构CdS∶Cu/CdS纳米晶为立方闪锌矿结构;与CdS纳米晶核相比,掺杂Cu2+可以使其表面态发光发生红移;在CdS∶Cu纳米晶中,通过改变掺杂Cu2+的浓度,可以实现表面态发光在570和620nm之间的连续调节.与未经包覆的CdS∶Cu纳米晶相比,包覆层CdS增强了纳米晶CdS∶Cu的稳定性. 相似文献
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对木棉纤维进行预处理,然后用预处理后木棉纤维与CdS进行原位复合制备木棉纤维/CdS纳米复合材料。利用扫描电镜(SEM)和原子力显微镜(AFM)对复合材料表面形貌结构进行了观察。用AFM定量地分析了预处理方法对木棉纤维/CdS纳米复合材料表面超微三维结构的影响。研究表明,相比未处理木棉纤维,预处理后木棉纤维/CdS纳米复合材料上CdS粒子的吸附量增大,且经过TEMPO氧化处理的木棉纤维所复合的CdS粒子的分布最均匀,粒径最均一。对于基于植物质纤维素资源为原料的纤维素/无机纳米复合材料的制备及其结构表征具有重要的参考价值。 相似文献
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CdS nanoparticles have been successfully synthesized by using DNA networks as templates. The synthesis was carried out by first dropping a mixture of cadmium acetate and DNA on a mica surface for the formation of the DNA network template and then transferring the sample into a heated thiourea solution. The Cd(2+) reacted with thiourea at high temperature and formed CdS nanoparticles on the DNA network template. UV-vis spectroscopy, photoluminescence, x-ray diffraction and atomic force microscopy (AFM) were used to characterize the CdS nanoparticles in detail. AFM results showed that the resulted CdS nanoparticles were directly aligned on the DNA network templates and that the synthesis and assembly of CdS nanoparticles was realized in one step. CdS nanoparticles fabricated with this method were smaller than those directly synthesized in a thiourea solution and were uniformly aligned on the DNA networks. By adjusting the density of the DNA networks and the concentration of Cd(2+), the size and density of the CdS nanoparticles could be effectively controlled and CdS nanoparticles could grow along the DNA chains into nanowires. The possible growth mechanism has also been discussed in detail. 相似文献
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Ying Zhao Xiu-chun Yang Wen-hai Huang Xiao Zou Zhen-guang Lu 《Journal of Materials Science》2010,45(7):1803-1808
CdS nanowires were prepared by a paired cell method, using highly ordered porous anodic alumina (PAA) membranes as templates.
The morphology, structure, and composition of these nanowires were characterized by scanning electron microscopy (SEM), high-resolution
transmission electron microscopy (HRTEM), energy dispersive X-ray spectroscopy (EDS), and selected area electron diffraction
(SAED) pattern. SEM images indicated that nanowires arrays are highly ordered and coincide with the contours of PAA. The EDS
analysis, combined with HRTEM images and SEAD patterns, confirmed the formation of CdS. The formation and growth mechanism
of CdS nanowires, as well as the optical properties, were also analyzed in details. The results indicated that the formation
and growth of CdS nanowires experience from initial nuclei, nanoparticles, linear pearl-chain structures to final nanowires,
attributed to electrostatic adsorption and ions diffusion. A strong emission with a maximum around 430 nm was observed from
the synthesized CdS nanowires, which was attributed to the recombination of trapped electron/hole pairs. The absorption edge
in UV–Vis spectrum of CdS/PAA nanoarrays showed a blue shift due to the quantum confinement effects. The technique can be
used to fabricate other compound nanowires and newly light-emitting semiconductor materials. 相似文献
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A convenient sonochemical route was developed to fabricate one-dimensional (1D) CdS or CdSe assemblies via a simple template method with two-steps: Firstly, the colloid one dimensional cadmium hydroxide particles were prepared as templates under sonication; then, the colloid particles were converted into 1D CdS or CdSe assemblies via a replacement reaction after the surface nucleation and crystal growth processes. The as-prepared CdS and CdSe nanowires were characterized by XRD, TEM, XPS, and UV-visible Spectroscopy. The effects of the ultrasonic irradiation were discussed. It is believed that the ultrasound irradiation played a positive role in both the assembly of the colloid cadmium hydroxide particles into the 1D structure and the growth of CdSe and CdS nanowires. The effects of pH on the morphologies of the cadmium hydroxide template were also discussed. The band gaps of the as-prepared 1D CdSe and CdS assemblies were calculated to be 3.1 eV and 4.9 eV, respectively, indicating the quantum size effect. The as-prepared products might have potential applications in nanodevices in future. 相似文献
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Writing and Functionalisation of Suspended DNA Nanowires on Superhydrophobic Pillar Arrays 下载免费PDF全文
Ermanno Miele Angelo Accardo Andrea Falqui Monica Marini Andrea Giugni Marco Leoncini Francesco De Angelis Roman Krahne Enzo Di Fabrizio 《Small (Weinheim an der Bergstrasse, Germany)》2015,11(1):134-140
Nanowire arrays and networks with precisely controlled patterns are very interesting for innovative device concepts in mesoscopic physics. In particular, DNA templates have proven to be versatile for the fabrication of complex structures that obtained functionality via combinations with other materials, for example by functionalisation with molecules or nanoparticles, or by coating with metals. Here, the controlled motion of the a three‐phase contact line (TCL) of DNA‐loaded drops on superhydrophobic substrates is used to fabricate suspended nanowire arrays. In particular, the deposition of DNA wires is imaged in situ, and different patterns are obtained on hexagonal pillar arrays by controlling the TCL velocity and direction. Robust conductive wires and networks are achieved by coating the wires with a thin layer of gold, and as proof of concept conductivity measurements are performed on single suspended wires. The plastic material of the superhydrophobic pillars ensures electrical isolation from the substrate. The more general versatility of these suspended nanowire networks as functional templates is outlined by fabricating hybrid organic–metal–semiconductor nanowires by growing ZnO nanocrystals onto the metal‐coated nanowires. 相似文献
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We describe the conformational behavior and morphological control of DNA-mineralized CdS nanowires in a bulk solution. The conformational behavior of individual double-stranded DNA in the presence of cadmium ions and stoichiometric mixtures of cadmium ions and sulfide ions was directly visualized by fluorescence microscopy. It was found that in the presence of mixtures of cadmium ions and sulfide ions, DNA molecules exhibit a conformational transition from an elongated coil to a compacted state. Mineralized DNA nanowires possess a significant conformational freedom at a microscale, and flexibility in the micro- and nanodimensions. The density of the inorganic material on the nanowire can be controlled by varying the concentrations and the molar ratio of Na(2)S to Cd(ClO(4))(2). 相似文献
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《Journal of Experimental Nanoscience》2013,8(7-8):965-970
We developed a facile solvothermal route to various CdS nanocrystals in diethylenetriamine. Well-crystalline CdS nanowires and flower-like CdS nanocrystals were obtained at temperatures 220°C and 200°C, respectively. The nanowires have smooth surfaces and are grown along polar [0?0?0?1] direction. The flower-like CdS nanocrystals have hierarchical architectures composed of fine nanowires with lengths up to 10?µm. The effects of temperature on the morphology and structure of the final products are also investigated. The experimental observations indicates that high temperature facilitates fabricate CdS nanocrystals with regular morphology and excellent crystallisation. Moreover, it is found that organic solvent diethylenetriamine plays an important role in the growth of CdS nanocrystals. Diethylenetriamine can bind Cd2+ ions to form intermediate complex, resulting in final CdS nanocrystals with regular morphologies. 相似文献
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Helix-coiled gold nanowires were fabricated by a templating route using unique composite templates consisting of anodic aluminum oxide (AAO) nanotubular membrane and confined mesoporous silica therein. A different degree of confinement energy induces a different degree of helix curvature of confined porous silica nanochannels in an AAO, which works as a hard template for the electrochemical deposition of gold, thereby rationally enabling a different degree of helix curvature of gold nano-replicas. From surface-enhanced Raman scattering experiments, we first found that helix-coiled gold nanowires show more distinctly enhanced molecule sensing efficiency than those from simple smooth gold nanowires, and gold nanowires with the narrower lateral width show more enhanced molecule sensing efficiency than those of thicker width helix nanowires. 相似文献
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M. H. Akhlaghi M. R. Mohammadi 《Journal of Materials Science: Materials in Electronics》2013,24(9):3564-3574
In the present work a new strategy for straightforward fabrication of CdS/CdTe solar cells, containing CdS nanowires and nanoparticles as a window layer and CdTe nanoparticles and microparticles as an absorber layer, are reported. CdS and CdTe nanostructures were synthesized by solvothermal method. X-ray diffraction analysis revealed that highly pure and crystallized CdS nanowires and nanoparticles with hexagonal structure and CdTe nanoparticles with cubic structure were obtained. Atomic force microscope and field emission scanning electron microscope images showed that CdS nanowires with length of several μm and average diameter of 35 nm, CdS nanoparticles with average particle size of 32 nm and CdTe nanoparticles with average particle size of 43 nm, were uniformly coated on the substrate by the homemade formulated pastes. Based on ultraviolet–visible absorption spectra, the band gap energies of CdS nanowires, CdS nanoparticles and CdTe nanoparticles were calculated 2.80, 2.65 and 1.64 eV, respectively. It was found that, the photovoltaic performance of the solar cells depends on thickness of CdTe and CdS films, reaching a maximum at a specific value of 6 μm and 225 nm, respectively. For such cell made of CdS nanowires and CdTe nanoparticles the VOC, JSC, fill factor and power conversion efficiency were calculated 0.62 V, 6.82 mA/cm2, 59.7 and 2.53 %, respectively. Moreover, photovoltaic characteristics of the solar cells were dependent on CdTe and CdS morphologies. CdS/CdTe solar cell made of CdTe and CdS nanoparticles had the highest cell efficiency (i.e., 2.73 %) amongst all fabricated solar cells. The presented strategy would open up new concept for fabrication of low-cost CdS/CdTe solar cells due to employment of a simple chemical route rather than the vapor phase methods. 相似文献