A Simple and High-Performance Hydrazine Sensor Based on Graphene Nano Platelets Supported Metal Nanoparticles

2013 ◽  
Vol 704 ◽  
pp. 246-251 ◽  
Author(s):  
Yi Liu ◽  
Bei Bei Li ◽  
Wei Wei ◽  
Qi Jin Wan ◽  
Nian Jun Yang
Keyword(s):  
Electron Microscope ◽  
Modified Electrode ◽  
High Performance ◽  
X Ray ◽  
Glass Carbon Electrode ◽  
Transmission Electron ◽  
Glass Carbon ◽  
Graphene Glass ◽  
Supported Metal Nanoparticles ◽  
Hydrazine Sensor

Gold-palladium nanoparticles (AuPd NPs) were prepared on a layer of graphene (GR) film by potentiostatic electrodeposition from a mixture electrolyte of HAuCl4and H2PdCl4to fabricate the AuPdNPs/graphene/glass carbon electrode (AuPd/GR/GCE). The synthesized composite has been characterized using scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD) and energy dispersive X-ray spectroscopy (EDX). Electrocatalytic oxidation of hydrazine on the surface of modified electrode was investigated with cyclic voltammetry and chronoamperometry methods, the results showed that theAuPd NPshigh catalysis for the electrochemical oxidation of hydrazine and the excellent conductivity of graphene. Electrocatalytic activity of the modified electrode was investigated for the oxidation of hydrazine in 0.1 M phosphate buffer solutions (pH=6.0). Under the optimized conditions, the oxidation current of hydrazine was linear to its concentration in the range of 2185 μM, and the estimated detection limit was 0.2 μM (S/N =3).

Molybdenum Trioxide Dihydrate-Graphene Composite for Electrochemical Detection of Thiourea Molecule

NANO ◽  
2016 ◽  
Vol 11 (03) ◽  
pp. 1650036 ◽  
Author(s):  
Xinmeng Zhang ◽  
Kezhi Li ◽  
Hejun Li ◽  
Jinhua Lu ◽  
Leilei Zhang
Keyword(s):  
Electrochemical Sensor ◽  
Modified Electrode ◽  
Molybdenum Trioxide ◽  
Electrochemical Sensing ◽  
Carbon Electrode ◽  
X Ray ◽  
Glass Carbon Electrode ◽  
Graphene Composite ◽  
Relative Standard ◽  
Glass Carbon

A novel electrochemical sensing platform was constructed based on a facile self-assembly procedure synthetic laminar molybdenum trioxide dihydrate (MoO[Formula: see text]H2O)-graphene composite. Field emission scanning electron microscopy (FESEM), X-ray spectroscopy, X-ray diffraction (XRD) and Raman spectroscopy were employed to characterize the morphology and composition of the MoO[Formula: see text]H2O-graphene composite. As a model molecule, thiourea was utilized to investigate the electrochemical behaviors of the MoO[Formula: see text]H2O-graphene composite modified glass carbon electrode. The results show that the composite modified electrode has higher electron transfer rate than that of graphene modified electrode and bare glass carbon electrode meanwhile the peak currents of it has a good linear relationship with thiourea concentrations in the range of [Formula: see text] ([Formula: see text]) with detection limit of 4.99[Formula: see text][Formula: see text]M ([Formula: see text]). This novel electrochemical sensor exhibits a higher absorption capacity ([Formula: see text][Formula: see text]mol/cm2), a good reproducibility (1.41% relative standard deviation (RSD)), excellent anti-interference and a high stability. These excellent electrochemical properties of the MoO[Formula: see text]H2O-graphene composite are attributed to the loose and porous structure and the synergistic effects between graphene and MoO[Formula: see text]H2O, which make this composite material hold great potential applications for electrochemical sensor.

Facile hydrothermal synthesis of ternary CeO2–SnO2/rGO nanocomposite for supercapacitor application

2020 ◽  
Vol 13 (02) ◽  
pp. 2051005 ◽  
Author(s):  
Godlaveeti Sreenivasa Kumar ◽  
Somala Adinarayana Reddy ◽  
Hussen Maseed ◽  
Nagireddy Ramamanohar Reddy
Keyword(s):  
Electron Microscope ◽  
Specific Capacitance ◽  
High Performance ◽  
High Specific Capacitance ◽  
Energy Storage And Conversion ◽  
X Ray Diffraction ◽  
X Ray ◽  
Supercapacitor Application ◽  
Transmission Electron ◽  
One Step

In this work, we present the synthesis of a ternary CeO2–SnO2/rGO nanocomposite by using a facile one-step hydrothermal method. The as-synthesized composite was structural, chemical, morphological, elemental information studied by using different characterization techniques X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy and field emission scanning electron microscope (FESEM), energy dispersive X-ray spectroscopy (EDAX) and transmission electron microscope (TEM). The CeO2–SnO2/rGO exhibited an excellent specific capacitance of 156[Formula: see text]F[Formula: see text][Formula: see text] at 0.5[Formula: see text]A/g in the presence of 3 M KOH solution. The synergic effect of CeO2, SnO2 and graphene composite coated on Ni foam endowed a high specific capacitance than their individual compounds. This work suggests that the novel ternary composite is a promising candidate for the high performance electrochemical energy storage and conversion systems.

300kv high-performance analytical TEM (H-9000)

1987 ◽  
Vol 45 ◽  
pp. 108-109
Author(s):  
H. Kobayashi ◽  
H. Sato ◽  
K. Miyauchi ◽  
T. Onai ◽  
K. Shii ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Microscope ◽  
High Performance ◽  
Image Resolution ◽  
X Ray ◽  
Transmission Electron ◽  
Resolution Electron ◽  
Analytical Microscopy ◽  
High Resolution Electron Microscope

Higher voltage operation has many advantages for transmission electron microscopy.These advantages include better TEM image resolution and ease of specimen imaging. For analytical microscopy, the higher voltage operation has advantages such as higher source brightness, and better spatial resolution.We reported development of a 300kV ultra high resolution electron microscope. At this time, we would like to report an analytical type 300kV electron microscope.We have incorporated a side entry specimen stage which permits ±45° specimen tilt and is convenient for characteristic x-ray detection. We have also incorporated an analytical objective polepiece which has Cs of 2. 5mm, Cc of 2. 3mm and theoretical TEM image resolution of 0.23nm.

Direct growth of Mn0.6Ni0.4CO3 nanosheet assembles on Ni foam for high-performance supercapacitor electrodes

2022 ◽  
Author(s):  
RongMin Cheng ◽  
Conghong Zhan ◽  
Juanjuan Gao
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Powder Diffraction ◽  
High Performance ◽  
Ni Foam ◽  
X Ray ◽  
Transmission Electron ◽  
Direct Growth ◽  
Calcination Treatment ◽  
Scanning Electron

Using Ni foam as a template, Mn0.6Ni0.4CO3 nanosheet assembles were synthesized by hydrothermal method and calcination treatment. X-ray powder diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), Inductively...

A High-Performance Bimetallic Pd-Cu Nanoparticles Membrane on Glassy Carbon Electrode for Formic Acid Oxidation

2013 ◽  
Vol 704 ◽  
pp. 264-269 ◽  
Author(s):  
Wei Wei ◽  
Yi Liu ◽  
Qi Jin Wan ◽  
Nian Jun Yang
Keyword(s):  
Formic Acid ◽  
Modified Electrode ◽  
High Performance ◽  
Formic Acid Oxidation ◽  
Acid Oxidation ◽  
Carbon Electrode ◽  
Mixed Solution ◽  
Glass Carbon Electrode ◽  
Cu Content ◽  
Glass Carbon

The Palladium-copper nanoparticles (PdCu NPs) have been prepared by potentiostatic electrodeposition from a mixture electrolyte of H2PdCl4 and CuSO4,then placed the electrode in sulfuric acid using cyclic voltammetry sweep a few laps to fabricate the PdCu NPs/glass carbon electrode (Pd-Cu/GCE). The modified electrode electrochemical properties of a preliminary study found that this modified electrode has good stability and electrochemical activity, experiments show that formic aicd has good voltammetric response of the electrode. The electrical activity of the formic acid in the Pd/GCE is lower than that in the Pd-Cu/GCE, this is due to the synergistic effect of the bimetal. When the Cu content is increased gradually in H2PdCl4 and CuSO4 a mixed solution, the formic acid oxidation peak currentlower, because Cu has no electrocatalytic activity for formic acid oxidation.

X-ray microanalysis of thin specimens in the transmission electron microscope at voltages up to 1000 Kv.

1978 ◽  
Vol 36 (1) ◽  
pp. 540-541
Author(s):  
G. Cliff ◽  
M.J. Nasir ◽  
G.W. Lorimer ◽  
N. Ridley
Keyword(s):  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Weight Fraction ◽  
Present Series ◽  
Constant Independent ◽  
X Ray ◽  
Transmission Electron ◽  
Series Of Experiments ◽  
Image Position ◽  
X Ray Absorption

In a specimen which is transmission thin to 100 kV electrons - a sample in which X-ray absorption is so insignificant that it can be neglected and where fluorescence effects can generally be ignored (1,2) - a ratio of characteristic X-ray intensities, I1/I2 can be converted into a weight fraction ratio, C1/C2, using the equationwhere k12 is, at a given voltage, a constant independent of composition or thickness, k12 values can be determined experimentally from thin standards (3) or calculated (4,6). Both experimental and calculated k12 values have been obtained for K(11<Z>19),kα(Z>19) and some Lα radiation (3,6) at 100 kV. The object of the present series of experiments was to experimentally determine k12 values at voltages between 200 and 1000 kV and to compare these with calculated values.The experiments were carried out on an AEI-EM7 HVEM fitted with an energy dispersive X-ray detector.

Aspects of microanalysis in a transmission electron microscope

1978 ◽  
Vol 36 (1) ◽  
pp. 510-511
Author(s):  
R. Sinclair ◽  
B.E. Jacobson
Keyword(s):  
Grain Size ◽  
Electron Beam ◽  
Electron Microscope ◽  
Chemical Analysis ◽  
Transmission Electron Microscope ◽  
Vapor Deposition ◽  
Critical Currents ◽  
X Ray ◽  
Fine Grain ◽  
Transmission Electron

INTRODUCTIONThe prospect of performing chemical analysis of thin specimens at any desired level of resolution is particularly appealing to the materials scientist. Commercial TEM-based systems are now available which virtually provide this capability. The purpose of this contribution is to illustrate its application to problems which would have been intractable until recently, pointing out some current limitations.X-RAY ANALYSISIn an attempt to fabricate superconducting materials with high critical currents and temperature, thin Nb3Sn films have been prepared by electron beam vapor deposition [1]. Fine-grain size material is desirable which may be achieved by codeposition with small amounts of Al2O3 . Figure 1 shows the STEM microstructure, with large (∽ 200 Å dia) voids present at the grain boundaries. Higher quality TEM micrographs (e.g. fig. 2) reveal the presence of small voids within the grains which are absent in pure Nb3Sn prepared under identical conditions. The X-ray spectrum from large (∽ lμ dia) or small (∽100 Ǻ dia) areas within the grains indicates only small amounts of A1 (fig.3).

Thickness and composition determinations from T.E.M. specimens using both x-ray and backscattered electron data

1984 ◽  
Vol 42 ◽  
pp. 576-577
Author(s):  
M.D. Ball ◽  
H. Lagace ◽  
M.C. Thornton
Keyword(s):  
Electron Microscope ◽  
Atomic Number ◽  
Transmission Electron Microscope ◽  
Convenient Method ◽  
Flow Chart ◽  
X Ray ◽  
Intensity Measurements ◽  
Transmission Electron ◽  
Electron Intensity ◽  
Backscattered Electron

The backscattered electron coefficient η for transmission electron microscope specimens depends on both the atomic number Z and the thickness t. Hence for specimens of known atomic number, the thickness can be determined from backscattered electron coefficient measurements. This work describes a simple and convenient method of estimating the thickness and the corrected composition of areas of uncertain atomic number by combining x-ray microanalysis and backscattered electron intensity measurements.The method is best described in terms of the flow chart shown In Figure 1. Having selected a feature of interest, x-ray microanalysis data is recorded and used to estimate the composition. At this stage thickness corrections for absorption and fluorescence are not performed.

PHAX-SCAN: Functional integration of a Scanning Electron Microscope and an energy-dispersive x-ray analyser

1989 ◽  
Vol 47 ◽  
pp. 56-57
Author(s):  
Marc H. Peeters ◽  
Max T. Otten
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
High Speed ◽  
High Performance ◽  
Functional Integration ◽  
Energy Dispersive ◽  
X Rays ◽  
X Ray ◽  
High Speed Analysis ◽  
Scanning Electron

Over the past decades, the combination of energy-dispersive analysis of X-rays and scanning electron microscopy has proved to be a powerful tool for fast and reliable elemental characterization of a large variety of specimens. The technique has evolved rapidly from a purely qualitative characterization method to a reliable quantitative way of analysis. In the last 5 years, an increasing need for automation is observed, whereby energy-dispersive analysers control the beam and stage movement of the scanning electron microscope in order to collect digital X-ray images and perform unattended point analysis over multiple locations.The Philips High-speed Analysis of X-rays system (PHAX-Scan) makes use of the high performance dual-processor structure of the EDAX PV9900 analyser and the databus structure of the Philips series 500 scanning electron microscope to provide a highly automated, user-friendly and extremely fast microanalysis system. The software that runs on the hardware described above was specifically designed to provide the ultimate attainable speed on the system.

High Spatial Resolution Compositional Analysis at Interfaces

1980 ◽  
Vol 38 ◽  
pp. 356-359
Author(s):  
John B. Vander Sande ◽  
Thomas F. Kelly ◽  
Douglas Imeson
Keyword(s):  
Electron Microscope ◽  
High Spatial Resolution ◽  
Compositional Analysis ◽  
Scanning Transmission Electron Microscope ◽  
Thin Specimen ◽  
X Ray ◽  
Volume Of Interest ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Electron Energy Loss

In the scanning transmission electron microscope (STEM) a fine probe of electrons is scanned across the thin specimen, or the probe is stationarily placed on a volume of interest, and various products of the electron-specimen interaction are then collected and used for image formation or microanalysis. The microanalysis modes usually employed in STEM include, but are not restricted to, energy dispersive X-ray analysis, electron energy loss spectroscopy, and microdiffraction.

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