Synthesis and morphological studies of ZnCuTe ternary nanowires via template-assisted electrodeposition technique

ZnCuTe nanowires have been successfully synthesized via template-assisted one step electrodeposition technique from an aqueous solution of zinc sulphate (ZnSO₄·7H₂O), copper sulphate (CuSO₄·5H₂O) and tellurium oxide (TeO₂) at room temperature (303?K). Nanowires of diameter 200, 100 and 50?nm have been synthesized on copper and indium tin oxide coated glass substrates using track-etch polycarbonate membranes (Whatman). The morphologies and structures of electrodeposited ZnCuTe nanowires were characterized by Scanning electron microscopy (SEM) and X-ray diffraction (XRD). SEM confirmed the formation of nanowires and reveal that the morphologies of nanowires have diameter equal to the diameter of the templates used. The XRD pattern have shown a preferential growth of ZnCuTe nanowires along the (119) direction and the structure corresponding to hexagonal structure. Energy dispersive X-ray analysis confirmed that the zinc copper telluride nanowires are constituted of elements Zn, Cu and Te.     

Synthesis of copper telluride nanowires using template-based electrodeposition method as chemical sensor

Copper telluride (CuTe) nanowires were synthesized electrochemically from aqueous acidic solution of copper (II) sulphate (CuSO₄·5H₂O) and tellurium oxide (TeO₂) on a copper substrate by template-assisted electrodeposition method. The electrodeposition was conducted at 30 °C and the length of nanowires was controlled by adjusting deposition time. Structural characteristics were examined using X-ray diffraction and scanning electron microscope which confirm the formation of CuTe nanowires. Investigation for chemical sensing was carried out using air and chloroform, acetone, ethanol, glycerol, distilled water as liquids having dielectric constants 1, 4·81, 8·93, 21, 24· 55, 42·5 and 80·1, respectively. The results unequivocally prove that copper telluride nanowires can be fabricated as chemical sensors with enhanced sensitivity and reliability.     

Controlled nanostructuring of multiphase core-shell nanowires by a template-assisted electrodeposition approach

Multiphase core-shell nanowires have been fabricated by controlling the ion transport processes of the microfluids in the nanochannels of the template. Both forced convection and pulsed potential induced migration can be applied to tune the morphologies of the nanostructures obtained by manipulating the ion transport during electrodeposition. The morphology and content of the core-shell structure were studied by field emission scanning electron microscope (FESEM) analysis, transmission electron microscope (TEM) analysis and energy dispersive spectrometry (EDS), respectively. The magnetic properties were analyzed by vibrating sample magnetometer (VSM) analysis. A magnetically hard core and soft shell constitutes the multiphase composite nanostructure. The unique magnetic hysteresis curve indicates the decoupled magnetic reversal processes of the two components. Our work provides deeper insights into the formation mechanisms of a new core-shell nanostructure, which may have potential applications in novel spintronics devices.     

Ultra-long periodically-twinned copper nanowires evolving from dendrites in interfacial electrodeposition

A simple and efficient template-free electrochemical route has been utilized to prepare ultra-long Cu nanowires at a steady water-oleic acid interface. The as-prepared nanowires have uniform diameters and aspect ratios of more than 1000, and periodically twinned structure. The investigation of the growth process has indicated that these nanowires actually evolve from the branches of dendrites. The morphology of the products can be tuned by controlling experimental parameters, such as electrodeposition time, metallic ions concentration, current density, the geometry of electric field and the property and state of the interfaces. The experimental results show that the steady water-oleic acid interface and a parallel electric field are crucial for the formation of dendritic Cu nanowires. It is believed that the higher Cu(2+) concentration near the water-oleic acid interface is favorable to induce interfacial electrodeposition. The electrochemical route is also suitable for the synthesis of other metal nanowires, such as Co nanowires.     

Synthesis and characterization of cadmium telluride nanowire

CdTe nanowires with controlled composition were cathodically electrodeposited using track-etched polycarbonate membrane as scaffolds and their material and electrical properties were systematically investigated. As-deposited CdTe nanowires show nanocrystalline cubic phase structures with grain sizes of up to 60 nm. The dark-field images of nanowires reveal that the crystallinity of nanowires was greatly improved from nanocrystalline to a few single crystals within nanowires upon annealing at 200?°C for 6?h in a reducing environment (5%?H(2)+95%?N(2)). For electrical characterization, a single CdTe nanowire was assembled across microfabricated gold electrodes using the drop-casting method. In addition to an increase in grain size, the electrical resistivity of an annealed single nanowire (a few 10(5)?Ω?cm) was one order of magnitude greater than in an as-deposited nanowire, indicating that crystallinity of nanowires improved and defects within nanowires were reduced during annealing. By controlling the dopants levels (e.g.?Te content of nanowires), the resistivity of nanowires was varied from 10(4) to 10(0)?Ω?cm. Current-voltage (I-V) characteristics of nanowires indicated the presence of Schottky barriers at both ends of the Au/CdTe interface. Temperature-dependent I-V measurements show that the electron transport mode was determined by a thermally activated component at T>-50?°C and a temperature-independent component below -50?°C. Under optical illumination, the single CdTe nanowire exhibited enhanced conductance.     

Synthesis and properties of copper phthalocyanine nanowires

Copper phthalocyanine (CuPc) nanowires were fabricated by organic vapor deposition. The nanowires were studied by scanning electron microscopy, X-ray diffraction, and absorption spectroscopy. The effect of the nature of substrate (glass, Si, indium tin oxide, fluorine doped tin oxide) and its temperature on the morphology and properties of the fabricated nanowires was studied. Deposition of a thin CuPc film before the nanostructure growth ensured high yield of CuPc nanowires for all the substrates except Si. The nanowire size and crystal structure were mainly determined by the substrate temperature, with α-CuPc nanowires obtained at the lowest temperature (∼ 190 °C) and β-CuPc nanowires obtained at higher temperatures (above 200 °C).     

Synthesis and characterization of phase-change nanowires

Phase-change memory materials have stimulated a great deal of interest although the size-dependent behaviors have not been well studied due to the lack of method for producing their nanoscale structures. We report the synthesis and characterization of GeTe and Sb(2)Te(3) phase-change nanowires via a vapor-liquid-solid growth mechanism. The as-grown GeTe nanowires have three different types of morphologies: single-crystalline straight and helical rhombohedral GeTe nanowires and amorphous curly GeO(2) nanowires. All the Sb(2)Te(3) nanowires are single-crystalline.     

Synthesis and characterization of srilankite nanowires

We describe the synthesis and characterization of srilankite (Ti2ZrO6) nanowires. The nanowires are produced via hydrothermal synthesis with a TiO2/ZrO2 mixture under alkaline conditions. The zirconium titanate nanowires have median diameters of 60 nm and median lengths of 800 nm with the (022) axis along the length of the nanowire. Electron microscopy, energy dispersive X-ray spectroscopy, powder X-ray diffraction, and electron diffraction are used to characterize the phases and compare nanowires produced with varying molar ratios of Ti and Zr. Electron diffraction patterns produced from single nanowires show highly crystalline nanowires displaying a compositional-ordering superlattice structure with Zr concentrated in bands within the crystal structure. This is in contrast to naturally occurring bulk srilankite where Zr and Ti are randomly substituted within the crystal lattice. Streaking is observed in the electron diffraction patterns suggesting short-range ordering within the superlattice structure.     

硒纳米线的合成及表征

采用对环境友好的绿色合成方法,在碱性条件下,利用氧化还原体系把高价硒还原成灰黑色的三方相硒.以蔗糖、葡聚糖为软模板和形态导向剂,制备出了尺寸均匀、形态不同的硒纳米线.并用XRD、SEM等分析手段对产物的形貌和结构进行了表征,并对它们的成线机理做了相应的分析和解释.结果表明,两种不同的糖对硒纳米线生长的影响不同,在蔗糖条...     

硫化锌纳米线的合成和表征

采用化学气相沉积法,以Zn(S2CNEt2)2为单源前驱体,Au为催化剂,在不同的温度下,得到了不同直径的六方相ZnS纳米线.在此基础上,改用Ni为催化剂,得到碳纳米管;改用单质S和Zn为原料,则得到立方相ZnS纳米线.在一定程度上实现了对ZnS纳米线的粒径和物相的控制合成,实现了利用催化剂对ZnS纳米线和碳纳米管的选择性合成.用X-射线粉末衍射(XRD)、扫描电镜(SEM)、透射电镜(TEM)和能量分散光谱(EDS)对合成产物进行了表征.     

Fabrication and characterization of novel nanostructured copper oxide films via a facile solution route

Nanostructured CuO film was prepared using glass or stainless steel slices as substrate via a simple ammonia-assisted solution route at 60 °C. The obtained CuO film was made up of well-crystallized nanosheets of 50-360 nm in thickness and 0.7-4.5 μm in width. The reaction time and the substrate have significant effects not only on the thickness, width, arrangement of the nanosheets but also on the morphology and the thickness of the films. The CuO film was characterized by SEM, TEM, XRD, IR, and Raman spectroscopy techniques.     

Synthesis and morphology analysis of electrospun copper nanowires

We report the fabrication of copper nanowires (NWs) using electrospinning technique. This processing technique was used successfully to synthesize copper NWs with various morphologies using a precursor composed of copper acetate salt and poly(vinyl) alcohol. The obtained NWs were characterized through high resolution scanning electron microscopy and atomic force microscopy and it was found that their morphology is sensitive to the applied voltage and solution flow rate. Their diameter decreased with increasing voltage and increasing flow rate. Moreover, at higher flow rate and lower voltage, the roughness of NWs became more pronounced. In addition, further improvement in NW morphology may be obtained with appropriate heat treatment. These copper NWs with varying morphologies and microstructures have potential applications in different engineering domains such as electronics, optoelectronics, and catalysis.     

Controlled fabrication of gold and polypyrrole nanowires with straight and branched morphologies via porous alumina template-assisted approach

Straight and branched nanowires (NWs) of gold and polypyrrole (PPy) were synthesized inside the pre-designed nanochannels of anodic aluminum oxide (AAO) templates via electrodeposition. The morphologies, diameters and lengths of the NWs could be tailored by tuning the topologies of the nanochannels inside the AAO template and electrodeposition parameters. The present method provides a rational way to build materials that can be electrodeposited inside the nanochannels into NWs with desired architectures, which have potentials in nanoelectronics and nanosystems.     

Synthesis and characterization of germanium oxide nanowires

Germanium oxide (GeO2) nanowires have been prepared by heating a mixture of Ge powder and carbon in an Ar + O2 mixture at 900 degrees C. The nanowires have been characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and spectroscopic measurements. The nanowires are single crystalline with diameters in the 15-250-nm range. They exhibit characteristic blue luminescence.     

立方相MgZnO纳米线的制备和表征

利用热蒸发方法,在硅衬底上制备出立方MgZnO纳米线。以Mg粉为源材料,所制备的为立方相MgO纳米线。以Mg粉和Zn粉混合物为源材料,可以制备出立方相MgZnO纳米线,Zn含量7%,直径200～300nm,具有单晶结构;同时产物中还包括六方相ZnO纳米线,直径30nm左右。MgZnO纳米线中Zn含量远低于源材料中的Zn含量,这可能是ZnO和Zn的蒸汽压远大于MgO和Mg的缘故。     

Obtaining ultra-long copper nanowires via a hydrothermal process

Ultra-long and uniform copper nanowires with controllable diameters of 30–100 nm, length up to several millimeters (aspect ratio >10⁵) and tunable crystallinity were obtained by hydrothermal processing the complex emulsion of copper (II) chloride and ODA at 120–180 °C. Both XRD pattern and EDX spectrum indicated that the products were pure copper without any observable impurities. It is observed by FESEM that the diameters and aspect ratios of the synthesized copper nanowires were influenced by the concentration of ODA and reaction temperature. HRTEM images and SAED patterns revealed that the crystallinity of copper nanowires were strongly dependent on the synthesis temperatures. Poly- and single-crystal copper nanowires were obtained at 120 °C and 180 °C, respectively.     

Synthesis and characterization of flower-like WS2 nanospheres via a facile hydrothermal route

Flower-like WS₂ nanospheres with high purity were successfully synthesized via a facile surfactant-assisted hydrothermal route. The products were characterized by X-ray powder diffraction and scanning electron microscopy. The flower-like WS₂ nanospheres, consisting of numerous aggregate nanosheets with the width of 300–500 nm, had uniform sizes with a mean diameter about 5 μm. Further comparative experiments showed that the surfactant cetyltrimethyl ammonium bromide (CTAB) played a critical role as templates to promote the growth of WS₂ nanosheets and accelerate the assembling of nanosheets into flower-like nanosphere. Interaction forces inside the CTAB made the flower-like nanospheres grow uniformly and dispersedly. Moreover, the WS₂ nanoflowers exhibited excellent visible-absorption ability and may have a potential application as a visible photocatalyst.     

Synthesis and characterization of anatase and rutile TiO2 nanorods by template-assisted method

Well-aligned anatase and rutile TiO₂ nanorods and nanotubes with a diameter of about 80–130 nm have successfully been fabricated via sol-gel template method. The prepared samples were characterized by using thermogravimetric (TG) and differential thermal analysis (DTA), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy dispersive X-ray spectroscopy (EDS). The XRD results indicated that the TiO₂ nanorods were crystallized in the anatase and rutile phases, after annealing at 400–800 °C for different periods of time from 0.2 to 10 h.     

Patterned procedure for template-synthesis and microstructural characterization of copper nanowires

Highly ordered circular patterns of copper nanowire arrays were successfully deposited into designed anodic aluminum oxide templates. High-resolution transmission electron microscopy was used to study the microstructure of these Cu nanostructures. The results showed that the growth orientation of the copper nanowires was along [220] direction, and the broken orientation were along [2?02?] and [02?2] directions, respectively. Regular cones were formed at the broken end of nanowires. Bent nanowires were also observed, this means that the copper nanowires have good mechanical properties when applied external force. Chemical analysis has been performed on Cu nanowires using electron energy-loss spectroscopy.