Papers by Keyword: Nanorod Array

Abstract: TiO₂ three-layer sol-gel films have been deposited on soda-lime silicate glass slides and dried in two different ways to study the effect of drying on thin film structure. The structural properties, surface topography and photocatalytic activity of the films were studied by X-ray diffraction, atomic force microscopy, and by analysing photocatalytic degradation of methyl orange, respectively. The titanium oxide sol-gel layers on glass slides dried at 20 °C before the deposition of next layers after final calcination at 500 °C resulted in a nanorod array film with good photocatalytic activity.

Abstract: Highly oriented and well-aligned ZnO nanorod arrays were synthesized by low-temperature solution phase method on copper substrate under different conditions. Results illustrated that dense ZnO nanorods were vertically and uniformly distributed on the substrate. The effects of precursor concentration, growth temperature and time on the morphologies of nanorod arrays were investigated systematically. It is demonstrated that the controllable growth of well-aligned ZnO nanorods can be realized by readily adjusting the preparation parameters. The high quality ZnO nanorod arrays could be achieved via the chemical approach at low temperature.

Abstract: A metallurgical method for preparing oxide nano-rod array structure was developed with internal oxidation of Ni(Al) solid solution obtained by aluminizing Ni with a pack cementation technique. The present method was applied in order to fabricate nano-rod array on the micro-channel surface of microreactor. A micro-channel with 1 mm in depth, 1mm in width and 10 mm in length was fabricated on the Ni disk by an electric discharge machining and electropolishing. The Ni disk with a micro-channel was annealed at 1300°C for 12 h in vacuum. The sample was aluminized by a pack cementation using pack powder mixture consisting of 10 mass% of Ni3Al, 88 mass% of Al2O3 and 2 mass% of NaCl at 1100°C for 12 h in a flow of argon gas. The sample was oxidized from 1000 to 1200°C for 6 h with the Co/CoO buffer. Ni matrix in internally oxidized zone was removed by electropolishing to expose nano-rods. Al2O3 nano-rod array located on the micro-channel surface was successfully fabricated with the proposed technique. Diameter and height of nano-rods were ranged from 100 to 300 nm and from 1.5 to 3 µm, respectively.

Abstract: A low-temperature controllable chemical bath deposition (CBD) method was demonstrated to prepare ZnO nanorod arrays. Our deposition technique includes the seeding and subsequent main CBD growth. The uniform growth ZnO nanorod arrays on the condensed ZnO seeding layer could be controlled by changing the processing parameters. Experiment results reveal that the ZnO nanorod arrays prepared under 0.03-0.05 M concentration with reaction temperature of 95 °C demonstrate the well-aligned orientation and optimum optical properties with high aspect ratio of ~21. The n-ZnO/p-NiO heterojunction electrode shows excellent rectifying behavior with extremely low leakage current. After the sensitization with N719, it is found that the degree of orientation and aspect ratio value play critical roles in the photovoltaic properties of solid-state dye-sensitized solar cells (SS-DSSCs).

Abstract: Well-aligned ZnO nanorod arrays with 100-200nm diameter and about 1μm length were vertically grown on quartz substrate at relatively low temperature by a solution deposition method. The effects of reactant ratio, water-bath temperature, growth time on crystal structure were discussed. Microstructure of the arrays was investigated using X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM), optical properties were examined using fluorescence spectrophotometer. The results show that a Zn/C₆H₁₂N₄ molar ratio of 1:1, bath temprature 70°C, growth time of 24h are the optimal condition for the preparation of densely distributed ZnO arrays. XRD and FE-SEM analysis confirmed that the ZnO nanorod is a single crystal with a wurtzite structure and the photoluminescence (PL) spectra exhibit coexistence properties of ultraviolet (UV), blue and green emissions.

Abstract: ZnO nanorod arrays were prepared using a chemical solution route on fluorine-doped SnO2 conductive glass pre-coated by a thin ZnO seed layer. Morphology, crystal structure and growth direction of the nanorod arrays were characterized by SEM and XRD respectively. The SEM results demonstrated that ordered arrays of ZnO nanorods grew vertically on the substrate. XRD measurement revealed the ZnO nanorods were grown along the [002] direction of the ZnO crystallites. Under optimal condition, ZnO nanorods with the average length about 6-7 μm and the diameters about 10nm at the tip and 150 nm at the base were obtained. The optical properties of ZnO nanorod arrays were characterized by transmittance spectra and photoluminescence measurement at room temperature.

Abstract: We are reporting here on an inexpensive and facile fabrication method for ZnO nanorod arrays by hydrothermal growth at low temperature (90°C). In our experiment, ZnO nanostructures were grown on glass substrate using an equimolar (0.1M) aqueous solution of Zn(NO3)2•6H2O (zinc nitrate hexahydrate) and C6H12N4 (HMTA) as precursors solution, and using ammonia solution to controlling the pH levels. It enable easily obtained arrayed ZnO nanorods on substrate, and nanowires which grown on nanorod arrays were identified after about 1 month in the air. The growth process of nanorods and the formation mechanism of nanowires were investigated.

Abstract: An aluminization process with controlled Al activity to form surface Ni(Al) zone was applied to fabricate ceramic nanorod array structures by using internal oxidation. The pack cementation with NaCl, Ni3Al and Al2O3 was adapted as the aluminization process to form surface Ni(Al) zone. With increasing Ni3Al concentration in pack powder mixture, Al content of surface Ni(Al) zone was increased. Nanorod array structures can be successfully obtained on Ni components with designed shape.

Abstract: This paper introduces a process for the growth of oxide nanorod, nanotube, and nanocable arrays that combines sol preparation and template-based electrophoretic deposition. Examples are shown that the sol electrophoretic deposition is an effective method for the formation of polycrystalline and single crystal oxide nanorod arrays, nanotube arrays and conformal coating of thin films of oxides on metal nanorods to produce metal-oxide core-shell nanocable arrays.

Abstract: In this research, nanoscale spatial resolution p-n junction photodetector arrays were developed using ZnO nanorod arrays grown on p-type silicon substrates. In order to optimize the nanorod array quality, an advanced combinatorial spreadsheet approach was used to optimize the Au catalyst thickness. The crystallinity of these as-grown ZnO nanorods’ was compared to that of bulk and thin film ZnO materials.