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Nanorod Arrays (nanorod + array)

Distribution by Scientific Domains

Polymers and Materials Science	80%
Chemistry	15%

Selected Abstracts

Solar Cells by Design: Photoelectrochemistry of TiO2 Nanorod Arrays Decorated with CdSe

ADVANCED FUNCTIONAL MATERIALS, Issue 12 2010
Jin Ho Bang
Abstract One-dimensional (1D) nanostructures of TiO2 are grown directly on transparent, conductive glass substrate using hydrothermal/solvothermal methods. When employed as a photoanode in photoelectrochemical cells, the vertically aligned TiO2 nanorod array exhibits slower charge recombination at electrolyte interface as compared to mesoscopic TiO2 particulate film. Electrochemical deposition of CdSe onto TiO2 nanorod array is carried out to extend absorption into visible light region. The role of CdSe-sensitized, 1D rutile TiO2 architecture in the solar cell design is discussed. [source]

Periodic TiO2 Nanorod Arrays with Hexagonal Nonclose-Packed Arrangements: Excellent Field Emitters by Parameter Optimization

ADVANCED FUNCTIONAL MATERIALS, Issue 15 2009
Yue Li
Abstract Periodic TiO2 nanorod arrays with hexagonal nonclose-packed (hncp) arrangements are synthesized by pulsed laser deposition (PLD) using polystyrene colloidal monolayers as templates and with subsequent annealing in air. The hncp-array formation is governed by in situ volume shrinkage of amorphous TiO2 nanorods in the crystallizing process during annealing. The array periodicity can easily be tuned by different sphere sizes of the colloidal template, whereas the distance between neighboring nanorods can be controlled by altering the background gas pressure during the PLD process, at a given periodicity for the nanorod array. Parameter-controlled growth is helpful for investigating and optimizing the parameter-dependent field-emission properties. The hncp nanorod array exhibits an enhanced field-emission (FE) performance compared to both particle films and nanorod arrays with top aggregation. With an increase in periodicity of a hncp nanorod array, the field-enhancement factor decreases and the turn-on FE field increases. FE characteristics can be further enhanced by increasing the distance between adjacent nanorods while maintaining the same periodicity. The parameter-optimized results suggest that the arrays with a smaller periodicity and a larger distance display the best FE performance and could be highly valuable for designing field-emission devices based on these periodic nanorod arrays. [source]

Embedding Ag Nanoparticles into MgF2 Nanorod Arrays,

ADVANCED FUNCTIONAL MATERIALS, Issue 11 2008
Yuping He
Abstract Using a unique glancing angle co-deposition technique, face-centered cubic Ag nanoparticles have been embedded into aligned polycrystalline MgF2 nanorods with different topological shapes, such as tilted, zigzag, vertical, and helical nanorods. The optical properties of the artificial nanocomposite materials, such as surface plasmon resonance and polarization absorbance, are determined by the size of the Ag nanoparticles as well as the alignment and shape of the MgF2 nanorod arrays. The combination of co-deposition and glancing angle deposition provides a unique way to design novel nanocomposite materials and doped nanorod arrays. [source]

One-Dimensional Quantum-Confinement Effect in ,-Fe2O3 Ultrafine Nanorod Arrays,

ADVANCED MATERIALS, Issue 19 2005
L. Vayssieres
A 1D quantum confinement effect in hematite thin films consisting of oriented ultrafine nanorod bundles (see Figure) is investigated by resonant inelastic x-ray scattering of synchrotron radiation. The direct observation of a substantial bandgap increase compared to bulk hematite is revealed. This finding shows that these low-dimensional nanomaterials may be used for the generation of hydrogen by solar illumination without applied bias. [source]

Cerium Vanadate Nanorod Arrays from Ionic Chelator-Mediated Self-Assembly,

ANGEWANDTE CHEMIE, Issue 20 2010
Junfeng Liu Dr.
Aufgereiht: Einheitliche Aggregate aus CeVO4 -Nanostäbchen (siehe Bild) entstehen durch Selbstorganisation in Gegenwart von Ethylendiamintetraessigsäure (EDTA) in wässrigen Medien. EDTA steuert das anisotrope Wachstum, indem es die aktiven Wachstumszentren bestimmter Kristallflächen blockiert, und vermittelt die Aggregation durch Bildung intermolekularer Wasserstoffbrücken. [source]

Solar Cells by Design: Photoelectrochemistry of TiO2 Nanorod Arrays Decorated with CdSe

Periodic TiO2 Nanorod Arrays with Hexagonal Nonclose-Packed Arrangements: Excellent Field Emitters by Parameter Optimization

Hydrothermal Growth: Polymer-Templated Hydrothermal Growth of Vertically Aligned Single-Crystal ZnO Nanorods and Morphological Transformations Using Structural Polarity (Adv. Funct.

ADVANCED FUNCTIONAL MATERIALS, Issue 18 2010
Mater.
Abstract Position-configurable, vertical, single-crystalline ZnO nanorod arrays are fabricated via a polymer-templated hydrothermal growth method at a low temperature of 93 °C. A sol-gel processed dense c -oriented ZnO seed layer film is employed to grow nanorods along the c -axis direction [0001] regardless of any substrate crystal mismatches. Here, one-beam laser-interference lithography is utilized to fabricate nanoscale holes over an entire 2-in. wafer during the preparation of the polymer template. As such, vertically aligned ZnO nanorods can be grown from the seed layer exposed at the bottom of each hole. Furthermore, morphological transformations of the ZnO nanorods into pencil-like, needle-like, tubular, tree-like, and spherical shapes are obtained by controlling the growth conditions and utilizing the structural polarity of the ZnO nanorods. [source]

Polymer-Templated Hydrothermal Growth of Vertically Aligned Single-Crystal ZnO Nanorods and Morphological Transformations Using Structural Polarity

ADVANCED FUNCTIONAL MATERIALS, Issue 18 2010
Ki Seok Kim
Abstract Position-configurable, vertical, single-crystalline ZnO nanorod arrays are fabricated via a polymer-templated hydrothermal growth method at a low temperature of 93 °C. A sol-gel processed dense c -oriented ZnO seed layer film is employed to grow nanorods along the c -axis direction [0001] regardless of any substrate crystal mismatches. Here, one-beam laser-interference lithography is utilized to fabricate nanoscale holes over an entire 2-in. wafer during the preparation of the polymer template. As such, vertically aligned ZnO nanorods can be grown from the seed layer exposed at the bottom of each hole. Furthermore, morphological transformations of the ZnO nanorods into pencil-like, needle-like, tubular, tree-like, and spherical shapes are obtained by controlling the growth conditions and utilizing the structural polarity of the ZnO nanorods. [source]

Periodic TiO2 Nanorod Arrays with Hexagonal Nonclose-Packed Arrangements: Excellent Field Emitters by Parameter Optimization

Embedding Ag Nanoparticles into MgF2 Nanorod Arrays,

Formation of Nb2O5 Nanotube Arrays Through Phase Transformation**,

ADVANCED MATERIALS, Issue 5 2008
C. Yan
The successful synthesis of monoclinic Nb2O5nanotube arrays (see figure) from pseudo-hexagonal Nb2O5 nanorod arrays is reported; the synthesis is based on phase transformation accompanied by void formation, where voids can be intriguingly generated during phase transformation. A key parameter for achieving nanotube growth is the energy difference between the pseudo-hexagonal and monoclinic Nb2O5 nanostructures, which determines the phase transformation. [source]

Site-specific deposition of Ag nanoparticles on ZnO nanorod arrays via galvanic reduction and their SERS applications

JOURNAL OF RAMAN SPECTROSCOPY, Issue 9 2010
Wei Song
Abstract A controllable heterostructure consisting of ZnO nanorod arrays with attached Ag nanoparticles at only one end has been synthesized via a facile and convenient galvanic reduction method. Scanning electron microscopic images of these nanostructures showed good selectivity of Ag deposition on the tip of ZnO nanorod arrays. The formation of these regular AgZnO heterogeneous nanorod arrays can be explained by a localization of the electrons at the ends of the ZnO nanorods after the electron transfer step. By tuning the reaction time and the concentration of silver nitrate, the density of Ag nanoparticles on the tip of ZnO nanorods can be well controlled. Owing to the introduction of Ag nanoparticles with different densities, the resulting AgZnO heterogeneous nanorod arrays have been proved to be a versatile substrate for surface-enhanced Raman scattering not only for common organic molecules but also for label-free protein detection. Copyright © 2009 John Wiley & Sons, Ltd. [source]

Low-Temperature Growth of Rutile Nanorod Thin Films and their Photon-Induced Property

JOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 12 2008
Jin-Ming Wu
Thin films of well-crystallized pure rutile nanorods were deposited on Ti substrates through a simple solution approach at a low temperature of 353 K. Field emission scanning electron microscopic and atomic force microscopic investigations revealed topographies of both quasi-aligned and less-aligned nanorod arrays, depending on Ti grain facets. X-ray diffraction and Raman spectra analysis verified that the deposited nanorod thin film was phase-pure rutile. This rutile nanorod was identified to be single crystalline growing along the [001] direction by high-resolution transmission electron microscopy. UV-Vis diffuse reflectance spectra estimated a remarkable red shift in responsive light for the nanorods when compared with that of bulk rutile. Under illumination of artificial solar light, the ability of the rutile nanorod film to aid photodegradation of rhodamine B in water was argued to be superior to the rutile nanoparticles isolated from commercial Degussa P25, which was attributed to the unique rod-like nanostructure. [source]

Modeling of ZnO nanorods for evanescent field optical sensors

PHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 10 2007
Sandra Börner
Abstract The optical wave guiding properties of ZnO nanorods are simulated and studied in detail using a block-iterative frequency-domain method and the results of a finite difference method as reference data. The simulations are performed for different wavelengths in the infrared spectral region that are related to specific gas absorption lines. Here both single ZnO nanorods and nanorod arrays with varying period lengths are investigated. The evanescent field distributions and penetration depths into the surrounding media are analyzed and compared as a function of wavelength and rod diameter. Our results give a general overview on the size range where ZnO nanorods may be used for evanescent field interaction based sensors for the detection of gas molecules like CO, CO2 or O2. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

The Growth of One-Dimensional Single-Crystalline AlN Nanostructures by HVPE and Their Field Emission Properties,

CHEMICAL VAPOR DEPOSITION, Issue 1-3 2010
Yun-Ki Byeun
Abstract Single-crystalline AlN nanostructures, such as thin films, nanoneedles, nanocolumns, and nanowires, depending on the controlled gas-flow ratio, are synthesized by halide vapor-phase epitaxy (HVPE). In comparison with a typical vapor/liquid/solid (VLS) mechanism for the growth of nanowires, well-aligned AlN nanorod arrays with diameters below 20,nm are grown on a catalyst-free Si substrate though a vapor/solid (VS) mechanism. Their structural and optical properties are measured by X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and photoluminescence (PL). In particular, AlN nanorods exhibit an excellent field emission property with a low turn-on field of 2.25,V,µm,1. The field enhancement factor is estimated to be about 784 due to well-aligned, needle-shaped, AlN nanorods. [source]