Effect of Redox Reaction Products on the Luminescence Switching Behavior in CePO4:Tb Nanorods

2013 ◽  
Vol 117 (19) ◽  
pp. 10031-10038 ◽  
Author(s):  
Guozhu Chen ◽  
Haiguang Zhao ◽  
Federico Rosei ◽  
Dongling Ma
Keyword(s):  
Redox Reaction ◽  
Switching Behavior ◽  
Reaction Products

Luminescence switching behavior through redox reaction in Ce3+ co-doped LaPO4:Tb3+ nanorods: Re-dispersible and polymer film

2011 ◽  
Vol 40 (43) ◽  
pp. 11571 ◽  
Author(s):  
Ganngam Phaomei ◽  
R. S. Ningthoujam ◽  
W. Rameshwor Singh ◽  
Romeo Singh Loitongbam ◽  
Naorem Shanta Singh ◽  
...  
Keyword(s):  
Polymer Film ◽  
Redox Reaction ◽  
Switching Behavior ◽  
Co Doped

scholarly journals Kinetics and Mechanism of Oxidation of L-Ascorbic Acid by Pt(IV)(aq) in Aqueous Hydrochloric Acid Medium

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Sadhana Senapati ◽  
S. P. Das ◽  
A. K. Patnaik
Keyword(s):  
Electron Transfer ◽  
Ascorbic Acid ◽  
Acid Medium ◽  
Redox Reaction ◽  
Transfer Reaction ◽  
Total Concentration ◽  
Activation Parameters ◽  
Order Rate Constant ◽  
Electron Transfer Reaction ◽  
Reaction Products

Reduction of [PtCl6]2− by L-ascorbic acid (H2ASc) in 0.1 M aqueous acid medium has been investigated spectrophotometrically under pseudo-first order condition at [PtCl6]2− = 0.005–0.007 mol dm−3, 0.05 ≤ [H2ASc]/mol dm−3 ≤ 0.3, 298 K ≤ T ≤ 308 K, [H+] = 0.14 mol dm−3, I=0.5 mol dm−3. The redox reaction follows the rate law: d[Pt(IV)]/dt = k[H2ASc][Pt(IV)], where k is the second-order rate constant and [H2ASc] is the total concentration of ascorbic acid. Electron transfer from [H2ASc] to Pt(IV) center leading to the release of two halide ions and formation of the reaction products, square planner Pt(II) halide complex, and dehydrated ascorbic acid is suggested. This redox reaction follows an outersphere mechanism as Pt(IV) complex is substituted inert. Activation parameters were calculated corresponding to rate of electron transfer reaction k. Activation parameters favor the electron transfer reaction.

scholarly journals Lithia/(Ir, Li2IrO3) nanocomposites for new cathode materials based on pure anionic redox reaction

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Si Yeol Lee ◽  
Yong Joon Park
Keyword(s):  
Cathode Materials ◽  
Redox Reaction ◽  
Redox Reactions ◽  
Milling Process ◽  
Pure Oxygen ◽  
Cyclic Performance ◽  
Reaction Products ◽  
New Approach ◽  
Step Heat Treatment ◽  
Lower Overpotential

Abstract Anionic redox reactions attributed to oxygen have attracted much attention as a new approach to overcoming the energy-density limits of cathode materials. Several oxides have been suggested as new cathode materials with high capacities based on anionic (oxygen) redox reactions. Although most still have a large portion of their capacity based on the cationic redox reaction, lithia-based cathodes present high capacities that are purely dependent upon oxygen redox. Contrary to Li-air batteries, other systems using pure oxygen redox reactions, lithia-based cathodes charge and discharge without a phase transition between gas and condensed forms. This leads to a more stable cyclic performance and lower overpotential compared with those of Li-air systems. However, to activate nanolithia and stabilize reaction products such as Li2O2 during cycling, lithia-based cathodes demand efficient catalysts (dopants). In this study, Ir based materials (Ir and Li2IrO3) were introduced as catalysts (dopants) for nanolithia composites. Oxide types (Li2IrO3) were used as source materials of catalyst because ductile metal (Ir) can hardly be pulverized during the milling process. Two types of Li2IrO3 were prepared and used for catalyst-sources. They were named ‘1-step Li2IrO3’ and ‘2-step Li2IrO3’, respectively, since they were prepared by ‘1-step’ or ‘2-step’ heat treatment. The nanocomposites prepared using lithia & 2-step Li2IrO3 presented a higher capacity, more stable cyclic performance, and lower overpotential than those of the nanocomposites prepared using lithia & 1-step Li2IrO3. The voltage profiles of the nanocomposites prepared using lithia & 2-step Li2IrO3 were stable up to a limited capacity of 600 mAh·g−1, and the capacity was maintained during 100 cycles. XPS analysis confirmed that the capacity of our lithia-based compounds is attributable to the oxygen redox reaction, whereas the cationic redox related to the Ir barely contributes to their discharge capacity.

scholarly journals Synthesis of Bis{meso-Tetrakis(4-N-alkylpyridiniumyl)porphyrinato}cerium and Its Redox Switching Behavior

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 790
Author(s):  
Toshio Nishino ◽  
Yasuyuki Yamada ◽  
Ayumi Yamamoto ◽  
Kentaro Tanaka
Keyword(s):  
Organic Solvent ◽  
Redox Reaction ◽  
Electrochemical Measurements ◽  
Switching Behavior ◽  
Porphyrin Complex ◽  
Double Decker ◽  
Reversible Redox ◽  
Redox Switching

A novel double-decker porphyrin complex, bis{meso-tetrakis(4-N-alkylpyridiniumyl)porphyrinato}cerium, was prepared. Electrochemical measurements revealed that this complex exhibited reversible redox waves corresponding to a 1e– redox reaction of the cerium center. Treating the complex alternately with an oxidant and a reductant resulted in the reversible redox switching between the oxidized and reduced states in an organic solvent.

Redox reaction of aqueous selenite with As-rich pyrite from Jiguanshan ore mine (China): Reaction products and pathway

2014 ◽  
Vol 47 ◽  
pp. 130-140 ◽  
Author(s):  
Mingliang Kang ◽  
Fabrizio Bardelli ◽  
Laurent Charlet ◽  
Antoine Géhin ◽  
Andrey Shchukarev ◽  
...  
Keyword(s):  
Redox Reaction ◽  
Reaction Products

Lead aspartate: a new en bloc stain for electron microscopy

1978 ◽  
Vol 36 (2) ◽  
pp. 34-35
Author(s):  
J.R. Walton
Keyword(s):  
Electron Microscopy ◽  
Calcium Ion ◽  
Enzyme Reaction ◽  
Lead Citrate ◽  
Reaction Products ◽  
En Bloc ◽  
Thin Sections ◽  
Lead Salts ◽  
Thin Sectioning ◽  
High Alkalinity

In electron microscopy, lead is the metal most widely used for enhancing specimen contrast. Lead citrate requires a pH of 12 to stain thin sections of epoxy-embedded material rapidly and intensively. However, this high alkalinity tends to leach out enzyme reaction products, making lead citrate unsuitable for many cytochemical studies. Substitution of the chelator aspartate for citrate allows staining to be carried out at pH 6 or 7 without apparent effect on cytochemical products. Moreover, due to the low, controlled level of free lead ions, contamination-free staining can be carried out en bloc, prior to dehydration and embedding. En bloc use of lead aspartate permits the grid-staining step to be bypassed, allowing samples to be examined immediately after thin-sectioning.Procedures. To prevent precipitation of lead salts, double- or glass-distilled H20 used in the stain and rinses should be boiled to drive off carbon dioxide and glassware should be carefully rinsed to remove any persisting traces of calcium ion.

Studies of Oxide Formation on Copper Thin Films by Electron Microscopy

1977 ◽  
Vol 35 ◽  
pp. 316-317
Author(s):  
G. G. Hembree ◽  
M. A. Otooni ◽  
J. M. Cowley
Keyword(s):  
Electron Microscopy ◽  
Electron Diffraction ◽  
Single Crystal ◽  
Crystal Surface ◽  
Crystal Defects ◽  
Diffraction Reflection ◽  
Reaction Products ◽  
Intermediate Energies ◽  
Crystal Films ◽  
Reflection Electron Microscopy

The formation of oxide structures on single crystal films of metals has been investigated using the REMEDIE system (for Reflection Electron Microscopy and Electron Diffraction at Intermediate Energies) (1). Using this instrument scanning images can be obtained with a 5 to 15keV incident electron beam by collecting either secondary or diffracted electrons from the crystal surface (2). It is particularly suited to studies of the present sort where the surface reactions are strongly related to surface morphology and crystal defects and the growth of reaction products is inhomogeneous and not adequately described in terms of a single parameter. Observation of the samples has also been made by reflection electron diffraction, reflection electron microscopy and replication techniques in a JEM-100B electron microscope.A thin single crystal film of copper, epitaxially grown on NaCl of (100) orientation, was repositioned on a large copper single crystal of (111) orientation.

Precipitation in silicon: Microanalysis

1988 ◽  
Vol 46 ◽  
pp. 474-475
Author(s):  
R.W. Carpenter
Keyword(s):  
Transition Metals ◽  
Spatial Resolution ◽  
Thin Foil ◽  
Precipitation Reaction ◽  
High Current ◽  
Reaction Products ◽  
Carbon And Nitrogen ◽  
Dielectric Layers ◽  
Precipitation Processes ◽  
Areas Of Interest

Interest in precipitation processes in silicon appears to be centered on transition metals (for intrinsic and extrinsic gettering), and oxygen and carbon in thermally aged materials, and on oxygen, carbon, and nitrogen in ion implanted materials to form buried dielectric layers. A steadily increasing number of applications of microanalysis to these problems are appearing. but still far less than the number of imaging/diffraction investigations. Microanalysis applications appear to be paced by instrumentation development. The precipitation reaction products are small and the presence of carbon is often an important consideration. Small high current probes are important and cryogenic specimen holders are required for consistent suppression of contamination buildup on specimen areas of interest. Focussed probes useful for microanalysis should be in the range of 0.1 to 1nA, and estimates of spatial resolution to be expected for thin foil specimens can be made from the curves shown in Fig. 1.

TEM characterization of reaction zone in a SiC fiber-reinforced titanium alloy

1988 ◽  
Vol 46 ◽  
pp. 738-739
Author(s):  
G. Das ◽  
R. E. Omlor
Keyword(s):  
Titanium Alloys ◽  
Reaction Zone ◽  
Carbon Layer ◽  
Fiber Reinforced ◽  
Reaction Products ◽  
Sic Fibers ◽  
Sic Fiber ◽  
The Matrix ◽  
Immense Potential

Fiber reinforced titanium alloys hold immense potential for applications in the aerospace industry. However, chemical reaction between the fibers and the titanium alloys at fabrication temperatures leads to the formation of brittle reaction products which limits their development. In the present study, coated SiC fibers have been used to evaluate the effects of surface coating on the reaction zone in the SiC/IMI829 system.IMI829 (Ti-5.5A1-3.5Sn-3.0Zr-0.3Mo-1Nb-0.3Si), a near alpha alloy, in the form of PREP powder (-35 mesh), was used a茸 the matrix. CVD grown AVCO SCS-6 SiC fibers were used as discontinuous reinforcements. These fibers of 142μm diameter contained an overlayer with high Si/C ratio on top of an amorphous carbon layer, the thickness of the coating being ∽ 1μm. SCS-6 fibers, broken into ∽ 2mm lengths, were mixed with IMI829 powder (representing < 0.1vol%) and the mixture was consolidated by HIP'ing at 871°C/0. 28GPa/4h.

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