Structural Properties Of Nanowires Research Articles

Growth of Mn-Co-Ni-O nanowires by pulsed laser deposition

Manganese-cobalt–nickel oxides (Mn-Co-Ni-O) materials have been widely applied as infrared detectors due to its superior thermistor properties and one-dimensional Mn-Co-Ni-O nanowires are expected to significantly enhance the detecting performance. We herein present a novel approach for successfully growing Mn0.79Co1.71Ni0.50O4 nanowires with Au as catalyst by pulsed laser deposition. The influence of growth parameters on the morphology and structural properties of nanowires was explored, and the optimal growth condition of nanowires was obtained. The growth mechanism of Mn-Co-Ni-O nanostructures under different oxygen partial pressure environments is discussed. The deep understanding of the underlying growth mechanism can stimulate more future research on fabrication of high-quality Mn-Co-Ni-O nanowires.

Photocatalytic hydrogen production performance of 1-D ZnO nanostructures: Role of structural properties

Synthesis of zinc oxide (ZnO) nanowires (NWs) grown via vapor-liquid-solid (VLS) process using Gold (Au) as a catalyst metal on aluminum-doped zinc oxide (AZO) seed layer is reported in the present work. During the growth procedure, the nucleation process helps us to obtain ZnO nanowires with Au on the tip, confirming the VLS growth mechanism. Different morphologies were obtained after the variation in the growth parameters in the VLS process, and further, their role in the photocatalytic performance was studied. Changes in the structural properties of nanowires allowed us to modify the aspect ratio and surface area of the nanostructures. X-ray diffraction (XRD) showed that the principal orientation of the nanowires was (002) in the present case. Scanning electron microscopy (SEM) showed the structural properties of 1-D nanostructures (nanowires), and statistical analysis revealed that the average diameter in the present case was found to be varied from 57 to 85 nm. Scanning transmission electron microscopy (STEM) technique revealed the different elements present on the surface of ZnO NWs. Further, the compositional profile of nanostructures was cross-verified using Energy dispersive Spectroscopy (EDS). Photoluminescence (PL) and UV Visible studies were employed to study the optical properties of nanowires. UV–Vis measurements showed the role of different structural properties of nanowires on the absorption spectra, especially in the visible region. The ZnO nanowires were tested as photocatalysts for hydrogen production from water splitting reaction, and it was found in particular nanowires with random orientation with optimal diameter distribution show the stable and highest photocatalytic performance.

Integration of VLS-Grown WO3 Nanowires into Sensing Devices for the Detection of H2S and O3.

The inspiration behind this research is the development of tungsten oxide (WO3) nanowires based, highly sensitive and selective sensing devices directly on the active sensing platform. WO3 one-dimensional nanowires were synthesized via the vapour-phase growth technique. This approach allows the production of well-aligned and uniform nanowires on alumina substrates with their diameter and length in the nanometer range. The morphological and structural properties of nanowires have been investigated by means of the field effect electron microscopy, grazing incidence X-ray diffraction, Raman spectroscopy, and X-ray photoelectron spectroscopy. Finally, the fabricated WO3 nanowire sensing devices and their gas sensing performance were investigated in the presence of different oxidizing and reducing gases (especially environmental gases) at different temperatures. The WO3 sensors demonstrate high performance toward H2S and O3 at the optimal working temperatures of 400 and 200 °C, respectively, with the detection limit in the ppb level.

Ammonia gas sensor based on SnO2 nanostructure with the enhanced sensing capability at low temperatures

ABSTRACTWe investigated the gas-sensing performance of tin oxide nanowires for ammonia gas at low temperature (∼ 50°C). Tin oxide nanostructures were deposited at 1000°C and 1100°C on gold-coated silicon substrates using the physical vapor deposition method. Gas-sensing measurements were made for ammonia gas at various strengths (i.e. 50, 100 and 200 ppm) and the sensing performance was compared at low temperature for both the samples e.g. nanostructures deposited at 1000°C and 1100°C. Due to the highly oriented structure, the sample deposited at 1000°C shows high sensing capability at low temperature as compared to the regular tetragonal phase observed at 1100°C. The morphological and structural properties of nanowires were systematically examined using the scanning electron microscopy and X-ray diffraction.

Effect of Ultraviolet Radiation on Structural Properties of Nanowires

Effect of Ultraviolet Radiation on Structural Properties of Nanowires

The influences of technological conditions and Au cluster islands on morphology of Ga2O3 nanowires grown by VLS method on GaAs substrate

The synthesis of semiconductor nanowires is more and more interested to the applications for building blocks of the innovative nano-sized devices and circuits, but the research and fabrication of these nanowires are also holding a number of difficulties and challenges. Among many different kinds of semiconductor nanowires, Ga2O3 is increasingly grown for many promising applications in nano-device production, namely nanowire LED and Laser. So far there are many synthesizing methods of semiconductor nanowires, among them the vapor–liquid–solid (VLS) method is simple, cheap and popular. However, when we use the VLS method for nanowire growth, various technological problems exist. This paper aims at investigating some influences of the growth technological conditions and Au metal catalyst on the morphology of Ga2O3 nanowire grown by VLS on GaAs substrate. The main considering factors include the different growing temperatures and times, the effects of Au diffusion, Au droplets formation, Au cluster islands formation, and gas volume of the growing tube/ampoule at the 10−1 torr low air pressure. The obtained experimental results regarding the structural properties of nanowires under these effects investigated by scanning electron microscopy, field emission scanning electron microscopy, high angle annular dark field and bright field, scanning transmission electron microscopy, energy-dispersive X-ray techniques, and focus ion beam are presented and discussed.