Preparation and Nonstoichiometric Property of wide Compositional Fe(III)-doped TiO2 (anatase)

2000 ◽  
Vol 15 (4) ◽  
pp. 967-973 ◽  
Author(s):  
N. Uekawa ◽  
Y. Kurashima ◽  
K. Kakegawa ◽  
Y. Sasaki
Keyword(s):  
Activation Energy ◽  
Heating Rate ◽  
Constant Temperature ◽  
Electronic Property ◽  
Photoelectron Spectroscopy ◽  
Composition Range ◽  
Electronic Conduction ◽  
Oxidation Method ◽  
X Ray ◽  
Tio2 Anatase

Fe(III)-doped TiO2 (anatase) was prepared by the oxidation of FexTiS2. Two calcination methods were used to oxidize FexTiS2. In the first, sulfide was calcined in air at a given temperature for 2 h. In the second method, the sulfide was heated in air at a finite heating rate (2.5 K/min) and then held at a constant temperature for 2 h. Fe(III) ions completely dissolved into TiO2 (anatase), forming Fe(III)-doped TiO2 (anatase), in the composition range of 0 ⩽ Fe/Ti ⩽ 0.3 (mole ratio). The properties of the obtained oxide depended on the oxidation method of FexTiS2. The electronic property and the valence stage of the Fe(III)-doped TiO2 (anatase) were examined. The activation energy of electronic conduction decreased with an increase of the doped amount of Fe(III) ions. The x-ray photoelectron spectroscopy result showed that the electron density on the Ti ion in the Fe(III)-doped TiO2 (anatase) was decreased by the Fe(III) doping.

TiO2 anatase nanotubes for the purification of uranium,arsenic and lead containing water: an X-ray Photoelectron Spectroscopy study

2009 ◽  
Vol 1171 ◽  
Author(s):  
Marco Bonato ◽  
Kristin Vala Ragnarsdottir ◽  
Geoffrey C. Allen
Keyword(s):  
Photoelectron Spectroscopy ◽  
Uv Light ◽  
Carbonyl Complexes ◽  
Spectroscopy Study ◽  
High Adsorption ◽  
X Ray ◽  
Tio2 Anatase ◽  
Major Species ◽  
Titania Photocatalyst ◽  
Ph Range

AbstractTiO2 anatase nanotubes synthesised via anodic oxidation were used as adsorbent for the uptake of U and Pb from aqueous solution and the photoremoval of As(III). An X-ray photoelectron spectroscopy study of the sorbent medium surface revealed a high adsorption of U and Pb at pH 8. The adsorption of the uranyl ion was enhanced in an anoxy (N2) atmosphere, because this prevents the formation of very stable carbonyl complexes. As(III) was adsorbed on TiO2 but in the presence of O2 and UV light was oxidized to As(V). XPS analysis revealed that in the pH range 3-9 As(V) was always the major species detected at the surface of the titania photocatalyst.

Grain Boundary Diffusion in Co/Cu and Co/Cr Magnetic Thin Films

1993 ◽  
Vol 313 ◽  
Author(s):  
John G. Holl-Pellerin ◽  
S.G.H. Anderson ◽  
P.S. Ho ◽  
K.R. Coffey ◽  
J.K. Howard ◽  
...  
Keyword(s):  
Thin Films ◽  
Activation Energy ◽  
Diffusion Coefficient ◽  
Grain Boundary ◽  
Photoelectron Spectroscopy ◽  
Boundary Diffusion ◽  
Magnetic Thin Films ◽  
Grain Boundary Diffusion ◽  
X Ray ◽  
Before And After

ABSTRACTX-ray photoelectron spectroscopy (XPS) has been used to investigate grain boundary diffusion of Cu and Cr through 1000 Å thick Co films in the temperature range of 325°C to 400°C. Grain boundary diffusivities were determined by modeling the accumulation of Cu or Cr on Co surfaces as a function of time at fixed annealing temperature. The grain boundary diffusivity of Cu through Co is characterized by a diffusion coefficient, D0gb, of 2 × 104 cm2/sec and an activation energy, Ea,gb, of 2.4 eV. Similarly, Cr grain boundary diffusion through Co thin films occurs with a diffusion coefficient, Do,gb, of 6 × 10-2cm2/sec and an activation energy, Ea,gb of 1.8 eV. The Co film microstructure has been investigated before and after annealing by x-ray diffraction and transmission electron Microscopy. Extensive grain growth and texturing of the film occurred during annealing for Co deposited on a Cu underlayer. In contrast, the microstructure of Co deposited on a Cr underlayer remained relatively unchanged upon annealing. Magnetometer Measurements have shown that increased in-plane coercivity Hc, reduced remanence squareness S, and reduced coercive squareness S* result from grain boundary diffusion of Cu and Cr into the Co films.

Anelastic Phenomena at the Fibre-Matrix Interface of the Ti6Al4V-SiCf Composite

2010 ◽  
Vol 425 ◽  
pp. 263-270 ◽  
Author(s):  
Paolo Deodati ◽  
Riccardo Donnini ◽  
Saulius Kaciulis ◽  
Alessio Mezzi ◽  
Roberto Montanari ◽  
...  
Keyword(s):  
Activation Energy ◽  
Relaxation Time ◽  
Photoelectron Spectroscopy ◽  
Chemical Characterization ◽  
Matrix Interface ◽  
Ion Sputtering ◽  
Mechanical Spectroscopy ◽  
Monolithic Alloy ◽  
X Ray ◽  
Fibre Matrix

The composite, consisting of Ti6Al4V matrix reinforced by unidirectional SiC fibres (SCS-6), has been investigated by mechanical spectroscopy at temperatures up to 1,173 K. For comparison, the same experiments have been performed on the corresponding monolithic alloy. The internal friction (IF) spectrum of the composite exhibits a new relaxation peak superimposed to an exponentially increasing background. This peak, which is not present in the monolithic alloy, has an activation energy H = 186 kJ mol-1 and a relaxation time 0 = 2.3 x 10-15 s. The phenomenon has been attributed to a reorientation of interstitial-substitutional pairs in the  phase of Ti6Al4V matrix around the fibres. This explanation is supported by the results of micro-chemical characterization carried out by X-ray photoelectron spectroscopy (XPS) combined with Ar ion sputtering.

An X-Ray Photoelectron Study of Doped and Supported Nickel Oxide

1985 ◽  
Vol 38 (9) ◽  
pp. 1293 ◽  
Author(s):  
SJ Cochran ◽  
FP Larkins
Keyword(s):  
Activation Energy ◽  
Electron Transport ◽  
Nickel Oxide ◽  
Photoelectron Spectroscopy ◽  
Oxide Surface ◽  
X Ray ◽  
Peak Intensity ◽  
Photoelectron Study ◽  
Supported Oxides ◽  
Doped Oxide

The surfaces of lithium-and chromium-doped nickel oxide and of nickel oxide supported on alumina have been examined by X-ray photoelectron spectroscopy. The concentration of the nickel(III) species increased for the lithium-doped oxide and decreased for the chromium-doped oxide relative to the undoped oxide. The effects of doping were manifested most clearly however by the amount of oxygen-containing species adsorbed on the oxide surface rather than by variations in the nickel(III) peak intensity. Lithium-doped oxides were also shown to reduce more readily than undoped or chromium-doped oxides in the presence of carbon-containing impurities. The rate of reduction is influenced by the activation energy for electron transport which is related to the availability of the nickel(III) species. Supported oxides showed significant surface enhancement of nickel(II) as well as an absence of the nickel(III) species. The nickel(II) species in the supported oxide was not easily reduced to nickel(0).

scholarly journals X-ray photoelectron spectroscopy data from lightly Pd doped TiO2 anatase nanoparticles

2020 ◽  
Vol 27 (2) ◽  
pp. 024011
Author(s):  
Mark H. Engelhard ◽  
Donald R. Baer ◽  
Linxiao Chen
Keyword(s):  
Photoelectron Spectroscopy ◽  
Spectroscopy Data ◽  
Doped Tio2 ◽  
X Ray ◽  
Tio2 Anatase ◽  
Anatase Nanoparticles

Transition in high-temperature oxidation kinetics of Pd-modified aluminide coatings: Role of oxygen partial pressure, heating rate, and surface treatment

2000 ◽  
Vol 15 (3) ◽  
pp. 665-675 ◽  
Author(s):  
Daniel Monceau ◽  
Karima Bouhanek ◽  
Raphaëlle Peraldi ◽  
André Malie ◽  
Bernard Pieraggi
Keyword(s):  
Heating Rate ◽  
Photoelectron Spectroscopy ◽  
Secondary Ion Mass Spectrometry ◽  
Alumina Scale ◽  
Isothermal Oxidation ◽  
Temperature Oxidation ◽  
X Ray ◽  
Aluminide Coatings ◽  
Kinetic Transition ◽  
Direct Growth

The isothermal oxidation of Pd-modified Ni aluminide coatings was studied as a function of Po2 and temperature (900–1200 °C). A kinetic transition was observed between 900 and 1000 °C. Grazing incident x-ray diffraction, thermogravimetric analysis, x-ray photoelectron spectroscopy, scanning electron microscopy/energy dispersive spectroscopy, and secondary ion mass spectrometry analyses are consistent with the growth of δ-alumina or α-alumina below or above this transition temperature. Moreover, because Po2 was established before specimen heating, an effect of heating rate was observed and analyzed. More importantly, no kinetic transition was observed for sand-blasted specimens oxidized at low Po2. Thus conditions for the direct growth of an α-alumina scale could be determined from the reported results.

scholarly journals Characterization and carbon monoxide oxidation activity of La1.ySryCr1.xRuxO3 perovskites

2000 ◽  
Vol 65 (1) ◽  
pp. 15-25 ◽  
Author(s):  
A. Terlecki-Baricevic ◽  
S. Petrovic ◽  
D. Jovanovic ◽  
Lj. Karanovic ◽  
C. Marinova
Keyword(s):  
Activation Energy ◽  
Photoelectron Spectroscopy ◽  
Fluorescence Analysis ◽  
Kinetic Studies ◽  
Bet Surface Area ◽  
Specific Rate ◽  
X Ray Diffraction ◽  
Oxidation Activity ◽  
X Ray ◽  
Recycle Reactor

The oxidation of CO over La1-y Sr y Cr1-xRuxO3 perovskite type oxides with y=0.3 and 0 ?x ?0.100 have been studied. X-ray fluorescence analysis confirmed that content of elements in the bulk corresponds to the established nominal perovskite stoichiometry, indicating that no significant oxidation of ruthenium into volatile polyvalent oxides with their consequented escape from the sample occurred in air up to the temperature of 1000?C. According to X-ray diffraction analysis, all sampls achieved the perovskite hexagonal with the presence of some SrCrO4. X-ray photoelectron spectroscopy analysis of ruthenium samples shows higher Ru and Sr surface concentrations than in the bulk. The binding energy for Ru3p is virtually the same in all samples and consistent with that of Ru 4+ (463.6.464.3eV). Kinetic studies were performed in a differential recycle reactor with a recycling ratio 80. The results show that substitution of Ru 4+ for Cr 3+ in La1-y Sr y CrO3 leads to a significant increase in both the activity and the activation energy. The global CO oxidation rate, referred on the BET surface area, correlates with the surface Ru 4+ atomic concentration. Hence, the activity reflect the surface enrichment in ruthenium. Moreover, an identical apparent activation energy E = 93 kJ/mol and the same specific rate per ruthenium surface ion were obtained for samples with a Ru content x ? 0.05 suggest that exposed Ru 4+ ions mainly participate in the reaction.

THERMAL AND STRUCTURAL INVESTIGATION OF NIOBIUM PHOSPHATE GLASSES

2006 ◽  
Vol 20 (06) ◽  
pp. 281-287 ◽  
Author(s):  
S. SIMON ◽  
DANA CACAINA ◽  
I. BALASZ
Keyword(s):  
Activation Energy ◽  
Heating Rate ◽  
Structural Investigation ◽  
Phosphate Glasses ◽  
X Ray Diffraction ◽  
Vitreous State ◽  
X Ray ◽  
Glass Stability ◽  
Activation Energy Of Crystallization ◽  
Niobium Phosphate

Glasses of the x( Nb 2 O 5· Li 2 O )(100-x)[ P 2 O 5· CaO ] system with 0≤x≤20 mol% were investigated by differential thermal analysis (DTA). The vitreous state of all samples was confirmed by X-ray diffraction analysis. Thermal differential data obtained at different heating rate were used to determine the activation energy of crystallization (Et), while the thermal stability was appreciated at the same heating rate for all samples. The glass stability is modified by the addition of Nb 2 O 5 and Li 2 O to the calcium-phosphate matrix.

Synthesis of coral-globular-like composite Ag/TiO2-SnO2 and its photocatalytic degradation of rhodamine B under multiple modes

2017 ◽  
Vol 76 (8) ◽  
pp. 2120-2132 ◽  
Author(s):  
Q. Song ◽  
L. Li ◽  
N. Zhuo ◽  
H. N. Zhang ◽  
X. Chen ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Photocatalytic Degradation ◽  
Rhodamine B ◽  
Photoelectron Spectroscopy ◽  
Diffuse Reflectance Spectroscopy ◽  
Organic Dyes ◽  
Uv Light ◽  
Sol Gel ◽  
X Ray ◽  
Tio2 Anatase

Taking cetyltrimethylammonium bromide (CTAB) as the template and using TiO2 as the substrate, coral-globular-like composite Ag/TiO2-SnO2 (CTAB) was successfully synthesized by the sol–gel combined with a temperature-programmed treatment method. X-ray diffraction, scanning electron microscopy (SEM), UV–vis diffuse reflectance spectroscopy, X-ray photoelectron spectroscopy, SEM combined with X-ray energy dispersive spectroscopy, and N2 adsorption–desorption tests were employed to characterize samples' crystalline phase, chemical composition, morphology and surface physicochemical properties. Results showed that composites not only had TiO2 anatase structure, but also had some generated SnTiO4, and the silver species was metallic Ag0. Ag/TiO2-SnO2 (CTAB) possessed a coral-globular-like structure with nanosheets in large quantities. The photocatalytic activity of Ag/TiO2-SnO2 (CTAB) had studied by degrading organic dyes under multi-modes, mainly using rhodamine B as the model molecule. Results showed that the coral-globular-like Ag/TiO2-SnO2 (CTAB) was higher photocatalytic activity than that of commercial TiO2, Ag/TiO2-SnO2, TiO2-SnO2 (CTAB), and TiO2-SnO2 under ultraviolet light irradiation. Moreover, Ag/TiO2-SnO2 (CTAB) composite can significantly affect the photocatalytic degradation under multi-modes including UV light, visible light, simulated solar light and microwave-assisted irradiation. Meanwhile, the photocatalytic activity of Ag/TiO2-SnO2 (CTAB) was maintained even after three cycles, indicating that the catalyst had good usability.

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