scholarly journals Toward the use of CVD-grown MoS2 nanosheets as field-emission source

2018 ◽  
Vol 9 ◽  
pp. 1686-1694 ◽  
Author(s):  
Geetanjali Deokar ◽  
Nitul S Rajput ◽  
Junjie Li ◽  
Francis Leonard Deepak ◽  
Wei Ou-Yang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Field Emission ◽  
Photoelectron Spectroscopy ◽  
High Performance ◽  
Flat Panel Displays ◽  
Field Emission Properties ◽  
Turn On ◽  
Transmission Electron ◽  
Vertically Aligned ◽  
20 Nm

Densely populated edge-terminated vertically aligned two-dimensional MoS2 nanosheets (NSs) with thicknesses ranging from 5 to 20 nm were directly synthesized on Mo films deposited on SiO2 by sulfurization. The quality of the obtained NSs was analyzed by scanning electron and transmission electron microscopy, and Raman and X-ray photoelectron spectroscopy. The as-grown NSs were then successfully transferred to the substrates using a wet chemical etching method. The transferred NSs sample showed excellent field-emission properties. A low turn-on field of 3.1 V/μm at a current density of 10 µA/cm2 was measured. The low turn-on field is attributed to the morphology of the NSs exhibiting vertically aligned sheets of MoS2 with sharp and exposed edges. Our findings show that the fabricated MoS2 NSs could have a great potential as robust high-performance electron-emitter material for various applications such as microelectronics and nanoelectronics, flat-panel displays and electron-microscopy emitter tips.

SYNTHESIS AND FIELD EMISSION PROPERTIES OF SnS2 AND In-DOPED SnS2 WITH HIERARCHICAL STRUCTURE

NANO ◽  
2011 ◽  
Vol 06 (05) ◽  
pp. 489-496 ◽  
Author(s):  
H. X. ZHONG ◽  
C. X. WANG
Keyword(s):  
Electron Microscopy ◽  
Field Emission ◽  
Photoelectron Spectroscopy ◽  
Sulfur Source ◽  
X Ray Diffraction ◽  
Hydrothermal Route ◽  
X Ray ◽  
Emission Properties ◽  
Field Emission Properties ◽  
Transmission Electron

A simple hydrothermal route was employed to prepare flower-like SnS2 and In -doped SnS2 by using biomolecular L-cysteine as sulfur source. The synthetic samples were characterized by X-ray diffraction, scanning electron microscopy, high resolution transmission electron microscopy, X-ray photoelectron spectroscopy and Raman spectroscopy in detail. Furthermore, the field emission from both the materials was investigated, it was found that both of them have excellent field emission properties, and the doped In has enhanced the field emission properties.

scholarly journals Ni2P/rGO/NF Nanosheets As a Bifunctional High-Performance Electrocatalyst for Water Splitting

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 744 ◽  
Author(s):  
Jinyu Huang ◽  
Feifei Li ◽  
Baozhong Liu ◽  
Peng Zhang
Keyword(s):  
Electron Microscopy ◽  
Water Splitting ◽  
Photoelectron Spectroscopy ◽  
High Performance ◽  
High Efficiency ◽  
Splitting Method ◽  
Bifunctional Catalyst ◽  
Strong Activity ◽  
X Ray ◽  
Transmission Electron

The hydrogen generated via the water splitting method is restricted by the high level of theoretical potential exhibited by the anode. The work focuses on synthesizing a bifunctional catalyst with a high efficiency, that is, a nickel phosphide doped with the reduced graphene oxide nanosheets supported on the Ni foam (Ni2P/rGO/NF), via the hydrothermal approach together with the calcination approach specific to the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER). The Raman, X-Ray Diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), Transmission Electron Microscope (TEM), Scanning Electron Microscopy (SEM), High-Resolution Transmission Electron Microscopy (HRTEM), as well as elemental mapping, are adopted to study the composition and morphology possessed by Ni2P/rGO/NF. The electrochemical testing is performed by constructing a parallel two-electrode electrolyzer (Ni2P/rGO/NF||Ni2P/rGO/NF). Ni2P/rGO/NF||Ni2P/rGO/NF needs a voltage of only 1.676 V for driving 10 mA/cm2, which is extremely close to Pt/C/NF||IrO2/NF (1.502 V). It is possible to maintain the current density for no less than 30 hours. It can be demonstrated that Ni2P/rGO/NF||Ni2P/rGO/NF has commercial feasibility, relying on the strong activity and high stability.

ZnO Nanostructures and Field Emission Properties on Cu Substrate Achieved by Electrodeposition Method

2011 ◽  
Vol 347-353 ◽  
pp. 3388-3391
Author(s):  
Jiang Feng Gong ◽  
Chang Yong Lan ◽  
Bo Zhang ◽  
Kai Xiao Zhang ◽  
Wei Hua Zhu
Keyword(s):  
Electron Microscopy ◽  
Field Emission ◽  
Growth Conditions ◽  
Zno Nanostructures ◽  
Emission Properties ◽  
Electrodeposition Method ◽  
Field Emission Properties ◽  
Field Emitters ◽  
Transmission Electron ◽  
Cu Substrates

In the present work, ZnO nanostructures with tunable size were successfully synthesized on non-seeded Cu substrates by a simple electrodeposition method. The effects of growth conditions on the morphology of the products were studied in detail by scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The as-prepared products exhibited flake-like morphology when the concentration of ZnCl2 was higher enough, while the products showed flower-like morphology when the concentration was lower enough. Field emission investigation indicated that the nanoflowers exhibited good emission properties. The ZnO nanoflowers show potential application as field emitters.

Synthesis of α–SiO2 nanowires using Au nanoparticle catalysts on a silicon substrate

2001 ◽  
Vol 16 (3) ◽  
pp. 683-686 ◽  
Author(s):  
Z. Q. Liu ◽  
S. S. Xie ◽  
L. F. Sun ◽  
D. S. Tang ◽  
W. Y. Zhou ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Large Scale ◽  
Device Fabrication ◽  
Au Nanoparticle ◽  
Large Panels ◽  
Transmission Electron ◽  
Temperature Scanning ◽  
Uniform Diameter ◽  
20 Nm

Large-scale SiO2 nanowires were synthesized by using a simple but an effective approach at low temperature. Scanning electron microscopy, transmission electron microscopy, and x-ray photoelectron spectroscopy were employed to characterize the samples. The results indicated that SiO2 nanowires with a uniform diameter of about 20 nm and a length up to 10 μm have been synthesized. Photoluminescence measurement showed that the SiO2 nanowires emitted blue light at 2.8 and 3.0 eV. The possible growth process of the SiO2 nanowires is discussed. Using this method, large panels of SiO2 nanowires can be made under conditions that are suitable for device fabrication.

ZnS NANOFLOWERS ON GRAPHENE FOR USE AS A HIGH-PERFORMANCE PHOTOCATALYST

NANO ◽  
2014 ◽  
Vol 09 (08) ◽  
pp. 1450097 ◽  
Author(s):  
ZENG BIN ◽  
LONG HUI
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
High Performance ◽  
Dye Degradation ◽  
Uv Light ◽  
Xps Spectra ◽  
X Ray ◽  
Transmission Electron ◽  
Photocatalytic Activities ◽  
Potential Applications

The nanocomposites of graphene loaded– ZnS nanoflowers (GR– ZnS ) had been successfully prepared. Materials were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectra (FTIR), photoluminescence (PL) and X-ray photoelectron spectroscopy (XPS) spectra. A possible formation mechanism of this architecture was proposed. The experimental results revealed that these nanoflowers exhibited excellent UV-light photocatalytic activities for pollutant methyl orange (MO) dye degradation. These new nanostructures were expected to show considerable potential applications in the water treatment.

Nanomeasurements in Transmission Electron Microscopy

2000 ◽  
Vol 6 (3) ◽  
pp. 224-230
Author(s):  
Z.L. Wang ◽  
P. Poncharal ◽  
W.A. de Heer
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Carbon Nanotube ◽  
Field Emission ◽  
Structural Damage ◽  
Measurement Techniques ◽  
Emission Properties ◽  
Field Emission Properties ◽  
Bending Modulus ◽  
Transmission Electron

Abstract Nanomaterials have attracted a great deal of research interest recently. The small size of nanostructures constrains the applications of well-established testing and measurement techniques, thus new methods and approaches must be developed for quantitative measurement of the properties of individual nanostructures. This article reports our progress in using in situ transmission electron microscopy to measure the electrical, mechanical, and field-emission properties of individual carbon nanotubes whose microstructure is well-characterized. The bending modulus of a single carbon nanotube has been measured by an electric field-induced resonance effect. A nanobalance technique is demonstrated that can be applied to measure the mass of a tiny particle as light as 22 fg (1 fg = 10−15 g), the smallest balance in the world. Quantum conductance was observed in defect-free nanotubes, which led to the transport of a superhigh current density at room temperature without heat dissipation. Finally, the field-emission properties of a single carbon nanotube are observed, and the field-induced structural damage is reported.

scholarly journals Effect of Time on a Hierarchical Corn Skeleton-Like Composite of CoO@ZnO as Capability Electrode Material for High Specific Performance Supercapacitors

2018 ◽  
Author(s):  
Anil Kumar Yedluri ◽  
Hee-Je Kim
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
High Performance ◽  
Energy Storage Devices ◽  
X Ray ◽  
Storage Devices ◽  
Transmission Electron ◽  
Potential Applications ◽  
Oxygen Groups ◽  
Cbd Method

CoO-ZnO-based composites have attracted considerable attention for the development of energy storage devices because of their multifunctional characterization and ease of integration with existing components. This paper reports the synthesis of CoO@ZnO (CZ) nanostructures on Ni foam by the CBD method for facile and eco-friendly supercapacitor applications. The formation of a CoO@ZnO electrode functioned with cobalt, zinc, nickel and oxygen groups was confirmed by X-ray diffraction, X-ray photoelectron spectroscopy, low and high-resolution of scanning electron microscopy, and transmission electron microscopy. The as-synthesized hierarchical nanocorn skeleton-like structure of CoO@ZnO-3h (CZ3h) electrode delivered a higher specific capacitance of 1136 F/g at a current density of 3 A/g with outstanding cycling stability, showing 98.3% capacitance retention over 3000 cycles in an aqueous 2 M KOH electrolyte solution. This retention was significantly better than that of other prepared electrodes, such as CoO (CO), ZnO (ZO), CoO@ZnO-1h (CZ1h), and CoO@ZnO-7h (CZ7h) (274, 383, 240 and 537 F/g, respectively). This superior capacitance was attributed to the ideal surface morphology of CZ3h, which is responsible for the rapid electron/ion transfer between the electrolyte and electrode surface area. The enhanced features of the CZ3h electrode highlight potential applications in high performance supercapacitors, solar cells, photocatalysis, and electrocatalysis.

scholarly journals Synthesis and Characterization of ZnO/ZnS Core/Shell Nanowires

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Taher Ghrib ◽  
Muneera Abdullah Al-Messiere ◽  
Amal Lafi Al-Otaibi
Keyword(s):  
Electron Microscopy ◽  
Thin Layer ◽  
Photoelectron Spectroscopy ◽  
Zno Nanowires ◽  
Core Shell ◽  
Wurtzite Phase ◽  
X Ray ◽  
Transmission Electron ◽  
20 Nm ◽  
Shell Nanowires

ZnO nanowires of approximately 3 µm length and 200 nm diameter are prepared and implanted vertically on substrate glass which is coated with thin layer of ITO which is too covered with bulk ZnO thin layer via electrodeposition process by cyclic voltammetry-chronoamperometry and with a chemical process that is described later; we have synthesized a ZnS nanolayer. ZnO/ZnS core/shell nanowires are formed by ZnO nanowires core surrounded by a very thin layer of porous ZnS shell principally constituted with a crystal which is about 15–20 nm in diameter. In the method, ZnS nanoparticles were prepared by reaction of ZnO nanowires with Na2S in aqueous solution at low temperature and also we have discussed the growth mechanism of ZnO/ZnS nanowires. The morphology, structure, and composition of the obtained nanostructures were obtained by using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). For the structure, SEM and XRD measurements indicated that the as-grown ZnO nanowires microscale was of hexagonal wurtzite phase with a high crystalline quality, and TEM shows that the ZnS is uniformly distributed on the surface of the ZnO nanowires.

Direct Growth of CuO Particles on Carbon Papers for High-Performance Rechargeable Li–O2 Batteries

2021 ◽  
Vol 21 (7) ◽  
pp. 3903-3908
Author(s):  
Inhan Kang ◽  
Jungwon Kang
Keyword(s):  
Electron Microscopy ◽  
Energy Efficiency ◽  
Field Emission ◽  
Photoelectron Spectroscopy ◽  
High Performance ◽  
Storage System ◽  
Energy Storage System ◽  
High Energy ◽  
Heating Process ◽  
X Ray

Lithium–oxygen (Li–O2) batteries are considered as a promising high-energy storage system. However, they suffer from overpotential and low energy efficiency. This study showed that CuO growth on carbon using facile synthesis (simple dipping and heating process) reduces overpotential, thus increasing the energy efficiency. We confirmed the structure of CuO on carbon using X-ray diffraction pattern, X-ray photoelectron spectroscopy, field-emission scanning electron microscopy, and field-emission transmission electron microscopy. The cathode of CuO on carbon shows an average overpotential reduction of ˜6% charge/discharge during 10 cycles in nonaqueous Li–O2 batteries. The possible reason for the reduced charge overpotential of the cathode of CuO on carbon is attributed to the formed Li2O2 of smaller particle size during discharging compared to pristine carbon.

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