Electrochemical Property of Terbium Doped Tantalum Oxide Film Electrode

2011 ◽  
Vol 301-303 ◽  
pp. 16-21 ◽  
Author(s):  
Yan Hong Zhao ◽  
Li Chun Hou ◽  
Wen Fei Liu ◽  
Sheng Liang ◽  
Xiao Jing Wang

Terbium doped tantalum oxide (Tb-Ta2O5) particles were synthesized with a low hydrothermal method. The phase structure of Tb-Ta2O5 obtained was performed by X-ray diffraction (XRD). The result revealed that the terbium doped Ta2O5 belongs to orthorhombic crystal. The electrochemical property of methylene blue (MB) at Tb-Ta2O5 film electrode in 0.5 mol dm-3 KCl aqueous solution was investigated with cyclic voltgrammetry (CV). The CV result indicated that the electrochemical kinetics of MB was diffusion controlling at Tb-Ta2O5 film electrode. Tb dopping imporved the electrochemical property of Ta2O5 film electrode. Tb-Ta2O5 is used as a kind of electrode material which has some new potential applications.

2011 ◽  
Vol 197-198 ◽  
pp. 261-264 ◽  
Author(s):  
Yan Hong Zhao ◽  
Li Chun Hou ◽  
Wen Fei Liu ◽  
Wen Ming Tong ◽  
Sheng Liang ◽  
...  

Cerium doped tantalum oxide (Ce-Ta2O5) particles were synthesized with hydrothermal method. The electrochemical behaviour of Ce-Ta2O5 film electrode in 0.1 mol dm-3 KCl containing 10 mmol dm-3 K3Fe(CN)6 was investigated with cyclic voltgrammetry (CV). The CV results indicated that the electrochemical reaction on the Ce-Ta2O5 film electrode exhibited stable electrochemical property. In addition, the phase structure of Ce-Ta2O5 prepared was performed by X-ray diffraction (XRD). The result revealed that the cerium doped Ta2O5 belongs to orthorhombic crystal.


2011 ◽  
Vol 197-198 ◽  
pp. 281-284 ◽  
Author(s):  
Yan Hong Zhao ◽  
Li Chun Hou ◽  
Xiang Li ◽  
Xiaodong Yang ◽  
Xiao Jing Wang

Tungsten doped tantalum oxide (W-Ta2O5) particles were synthesized by a low temperature hydrothermal method. The phase structure of W-Ta2O5particles was characterized by X-ray diffraction (XRD). The XRD results indicated that the samples belonged to orthorhombic crystal. The photocatalytic activity of samples was investigated with degradation methylene blue (MB) under ultraviolet light. The degradation efficiency of MB under the catalysis of W-Ta2O5particles attained 91% when the reaction time was 7 h. The kinetics of MB degradation was respect to the first-order in the presence of the photocatalysts.


2010 ◽  
Vol 156-157 ◽  
pp. 1440-1443
Author(s):  
Yan Hong Zhao ◽  
Min Sun ◽  
Shu Wei Wang ◽  
Wen Ming Tong ◽  
Xiao Jing Wang

The Ba doped tantalum oxide (Ba-Ta2O5) particles were synthesized using low temperature hydrothermal method. The phase structure of samples was characterized by X-ray diffraction (XRD). The result showed that Ba-Ta2O5 had still good crystallinity and belonged to rhombic crystal. The catalytic activity of samples was investigated with the degradation methylene blue (MB) under visible light. The degradation efficiency attained 82% when the reaction time was 12 h. The kinetics of MB degradation was respect to the first-order.


Author(s):  
A. Leineweber ◽  
M. Löffler ◽  
S. Martin

Abstract Cu6Sn5 intermetallic occurs in the form of differently ordered phases η, η′ and η′′. In solder joints, this intermetallic can undergo changes in composition and the state of order without or while interacting with excess Cu and excess Sn in the system, potentially giving rise to detrimental changes in the mechanical properties of the solder. In order to study such processes in fundamental detail and to get more detailed information about the metastable and stable phase equilibria, model alloys consisting of Cu3Sn + Cu6Sn5 as well as Cu6Sn5 + Sn-rich melt were heat treated. Powder x-ray diffraction and scanning electron microscopy supplemented by electron backscatter diffraction were used to investigate the structural and microstructural changes. It was shown that Sn-poor η can increase its Sn content by Cu3Sn precipitation at grain boundaries or by uptake of Sn from the Sn-rich melt. From the kinetics of the former process at 513 K and the grain size of the η phase, we obtained an interdiffusion coefficient in η of (3 ± 1) × 10−16 m2 s−1. Comparison of this value with literature data implies that this value reflects pure volume (inter)diffusion, while Cu6Sn5 growth at low temperature is typically strongly influenced by grain-boundary diffusion. These investigations also confirm that η′′ forming below a composition-dependent transus temperature gradually enriches in Sn content, confirming that Sn-poor η′′ is metastable against decomposition into Cu3Sn and more Sn-rich η or (at lower temperatures) η′. Graphic Abstract


2013 ◽  
Vol 834-836 ◽  
pp. 531-535
Author(s):  
Li Yan Yang ◽  
Yi Hui Guo ◽  
Li Li Yu ◽  
Jing You

A type of cross-linking starch microsphere (CSMs) has been synthesized via reversed phase suspension method. Crosslinked starch microsphere has good adsorption performance to metal ions in water. The adsorption kinetics of Co (II) on the CSMs, selectivity of adsorption CSMs towards Co (II),Cu (II),Pb (II),Cd (II) and adsorption effects of media towards Co (II) were investigated. The CSMs and its adsorption product were comparatively characterized by X-ray diffraction (XRD). The results showed that The adsorption rate is mainly controlled by liquid film diffusion, and the constant of adsorption rate is 0.0686min-1 at 308K. The crystal structure of the CSMs decreased greatly after the incorporation of Co (II). Co (II) has better adsorption selectivity on CSMs. Ions coexist and other substances in the solution have certain impact on adsorption. Those data are helpful for treatment of the wastewater containing heavy ions.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Mohamed S. Yahia ◽  
Ahmed S. Elzaref ◽  
Magdy B. Awad ◽  
Ahmed M. Tony ◽  
Ahmed S. Elfeky

Abstract Commercial Granulated Active Carbon (GAC) has been modified using 10 Gy dose Gamma irradiation (GAC10 Gy) for increasing its ability of air purification. Both, the raw and treated samples were applied for removing Chlorpyrifos pesticide (CPF) from ambient midair. Physicochemical properties of the two materials were characterized by Fourier Transform Infrared (FT-IR) and Raman spectroscopy. The phase formation and microstructure were monitored using X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), supported with Energy-Dispersive X-ray (EDX). The Surface area measurement was detected using BET particle size prosometry. Obtained outcomes showed that, the maximum adsorption capacity, given by Langmuir equations, was greatly increased from 172.712 to 272.480 mg/g for GAC and GAC10 Gy, respectively, with high selectivity. The overall removal efficiency of GAC10 Gy was notably comparable to that of the original GAC-sorbent. The present study indicated that, gamma irradiation could be a promising technique for treating GAC and turned it more active in eliminating the pesticides pollutants from surrounding air. The data of equilibrium has been analyzed by Langmuir and Freundlich models, that were considerably better suited for the investigated materials than other models. The process kinetics of CPF adsorbed onto both tested carbon versions were found to obey the pseudo first order at all concentrations with an exception at 70 mg/l using GAC, where, the spontaneous exothermic adsorption of Chlorpyrifos is a strong function for the pseudo-first order (PFO) and pseudo second order (PSO) kinetics.


Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3103
Author(s):  
Laurent Gremillard ◽  
Agnès Mattlet ◽  
Alexandre Mathevon ◽  
Damien Fabrègue ◽  
Bruno Zberg ◽  
...  

Due to growing demand for metal-free dental restorations, dental ceramics, especially dental zirconia, represent an increasing share of the dental implants market. They may offer mechanical performances of the same range as titanium ones. However, their use is still restricted by a lack of confidence in their durability and, in particular, in their ability to resist hydrothermal ageing. In the present study, the ageing kinetics of commercial zirconia dental implants are characterized by X-ray diffraction after accelerated ageing in an autoclave at different temperatures, enabling their extrapolation to body temperature. Measurements of the fracture loads show no effect of hydrothermal ageing even after ageing treatments simulated a 90-year implantation.


Author(s):  
Ke Guo ◽  
Shaoyan Wang ◽  
Renfeng Song ◽  
Zhiqiang Zhang

AbstractLeaching titaniferous magnetite concentrate with alkali solution of high concentration under high temperature and high pressure was utilized to improve the grade of iron in iron concentrate and the grade of TiO2 in titanium tailings. The titaniferous magnetite concentrate in use contained 12.67% TiO2 and 54.01% Fe. The thermodynamics of the possible reactions and the kinetics of leaching process were analyzed. It was found that decomposing FeTiO3 with NaOH aqueous solution could be carried out spontaneously and the reaction rate was mainly controlled by internal diffusion. The effects of water usage, alkali concentration, reaction time, and temperature on the leaching procedure were inspected, and the products were characterized by X-ray diffraction, scanning electron microscope, and energy dispersive spectroscopy, respectively. After NaOH leaching and magnetic separation, the concentrate, with Fe purity of 65.98% and Fe recovery of 82.46%, and the tailings, with TiO2 purity of 32.09% and TiO2 recovery of 80.79%, were obtained, respectively.


Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 10
Author(s):  
Daria V. Mamonova ◽  
Anna A. Vasileva ◽  
Yuri V. Petrov ◽  
Denis V. Danilov ◽  
Ilya E. Kolesnikov ◽  
...  

Surfaces functionalized with metal nanoparticles (NPs) are of great interest due to their wide potential applications in sensing, biomedicine, nanophotonics, etc. However, the precisely controllable decoration with plasmonic nanoparticles requires sophisticated techniques that are often multistep and complex. Here, we present a laser-induced deposition (LID) approach allowing for single-step surface decoration with NPs of controllable composition, morphology, and spatial distribution. The formation of Ag, Pt, and mixed Ag-Pt nanoparticles on a substrate surface was successfully demonstrated as a result of the LID process from commercially available precursors. The deposited nanoparticles were characterized with SEM, TEM, EDX, X-ray diffraction, and UV-VIS absorption spectroscopy, which confirmed the formation of crystalline nanoparticles of Pt (3–5 nm) and Ag (ca. 100 nm) with plasmonic properties. The advantageous features of the LID process allow us to demonstrate the spatially selective deposition of plasmonic NPs in a laser interference pattern, and thereby, the formation of periodic arrays of Ag NPs forming diffraction grating


1988 ◽  
Vol 119 ◽  
Author(s):  
Hung-Yu Liu ◽  
Peng-Heng Chang ◽  
Jim Bohlman ◽  
Hun-Lian Tsai

AbstractThe interaction of Al and W in the Si/SiO2/W-Ti/Al thin film system is studied quantitatively by glancing angle x-ray diffraction. The formation of Al-W compounds due to annealing is monitored by the variation of the integrated intensity from a few x-ray diffraction peaks of the corresponding compounds. The annealing was conducted at 400°C, 450°C and 500°C from 1 hour to 300 hours. The kinetics of compound formation is determined using x-ray diffraction data and verified by TEM observations. We will also show the correlation of the compound formation to the change of the electrical properties of these films.


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