Effects of Potassium Chemisorption on the Electronic Structure of VxOy/TiO2 Surfaces

1996 ◽  
Vol 454 ◽  
Author(s):  
Fulvio Parmigiani ◽  
Laura E. Depero ◽  
Luigi Sangaletti
Keyword(s):  
Electronic Structure ◽  
Valence Band ◽  
Photoelectron Spectroscopy ◽  
Open Shell ◽  
Band Edge ◽  
X Ray ◽  
Core Line ◽  
Band Spectra ◽  
Gap States ◽  
Vanadium Ions

ABSTRACTX-ray photoelectron spectroscopy of pure and K chemisorbed VxOy/TiO2 powders are reported. Core-line and valence band spectra suggest the presence of vanadium open shell ions on the pure VxOy/TiO2 interface, whereas potassium vanadate seems to form after K chemisorption. That results in the presence of a significant amount of gap states, with vanadium character, just above the O2p band edge, for the pure VxOy/TiO2 powder, while K chemisorption, reducing significantly the open shell vanadium ions, quenches the gap emission in the XPS valence band spectra.

scholarly journals Determination of the valence band edge of Fe oxide nanoparticles dispersed in aqueous solution through resonant photoelectron spectroscopy from a liquid microjet

2021 ◽  
Author(s):  
Giorgia Olivieri ◽  
Gregor Kladnik ◽  
Dean Cvetko ◽  
Matthew A. Brown
Keyword(s):  
Aqueous Solution ◽  
Electronic Structure ◽  
Valence Band ◽  
Photoelectron Spectroscopy ◽  
Band Edge ◽  
Photoemission Spectroscopy ◽  
Oxide Nanoparticles ◽  
Valence Band Edge ◽  
Resonant Photoemission

The electronic structure of hydrated nanoparticles can be unveiled by coupling a liquid microjet with a resonant photoemission spectroscopy.

BBonding in minerals: the application of PAX (photoelectron and X-ray) spectroscopy to the direct determination of electronic structure

1989 ◽  
Vol 53 (370) ◽  
pp. 153-164 ◽  
Author(s):  
David S. Urch
Keyword(s):  
Electronic Structure ◽  
Valence Band ◽  
Photoelectron Spectroscopy ◽  
Direct Determination ◽  
Energy Scale ◽  
X Ray ◽  
Electron Transitions ◽  
Dipole Selection Rule ◽  
The Individual

AbstractX-ray photoelectron spectroscopy can be used to measure the ionization energies of electrons in both valence band and core orbitals. As core vacancies are the initial states for X-ray emission, a knowledge of their energies for all atoms in a mineral enables all the X-ray spectra to be placed on a common energy scale. X-ray spectra are atom specific and are governed by the dipole selection rule. Thus the individual bonding roles of the different atoms are revealed by the fine structure of valence X-ray peaks (i.e. peaks which result from electron transitions between valence band orbitals and core vacancies). The juxtaposition of such spectra enables the composition of the molecular orbitals that make up the chemical bonds of a mineral to be determined.Examples of this approach to the direct determination of electronic structure are given for silica, forsterite, brucite, and pyrite. Multi-electron effects and developments involving anisotropic X-ray emission from single crystals are also discussed.

Electronic Structure of h-WO3 and CuWO4 Nanocrystals, Harvesting Materials for Renewable Energy Systems and Functional Devices

2011 ◽  
Vol 110-116 ◽  
pp. 2188-2193 ◽  
Author(s):  
V.V. Atuchin ◽  
I.B. Troitskaia ◽  
O.Yu. Khyzhun ◽  
V.L. Bekenev ◽  
Yu.M. Solonin
Keyword(s):  
Electronic Structure ◽  
Renewable Energy ◽  
Valence Band ◽  
Photoelectron Spectroscopy ◽  
Emission Spectroscopy ◽  
Energy Production ◽  
Energy Systems ◽  
Renewable Energy Systems ◽  
X Ray ◽  
Valence Band Region

— The electronic structure of hexagonal WO3 and triclinic CuWO4 nanocrystals, prospective materials for renewable energy production and functional devices, has been studied using the X-ray photoelectron spectroscopy (XPS) and X-ray emission spectroscopy (XES) methods. The present XPS and XES results render that the W 5d-and O 2p-like states contribute throughout the whole valence-band region of the h-WO3 and CuWO4 nanocrystalline materialls, however maximum contributions of the O 2p-like states occur in the upper, whilst the W 5d-like states in the lower portions of the valence band, respectively.

The Surface Analysis of Nickel Chromia Catalysts by X-Ray Photoelectron Spectroscopy

1973 ◽  
Vol 51 (10) ◽  
pp. 1670-1672 ◽  
Author(s):  
Norman Stewart McIntyre ◽  
Norman Henry Sagert ◽  
Rita Mary Louise Pouteau ◽  
Warren George Proctor
Keyword(s):  
Valence Band ◽  
Surface Analysis ◽  
Photoelectron Spectroscopy ◽  
Isotope Exchange ◽  
Surface Composition ◽  
X Ray ◽  
Hydrogen Water ◽  
Band Spectra ◽  
Composition Changes

The surface composition of a series of nickel–chromia catalysts has been examined by X-ray photoelectron spectroscopy. Correlation of the amount of available surface nickel with the activity of the particular catalyst for hydrogen water deuterium isotope exchange is very good. No significant alterations are observed in the valence band spectra as the surface composition changes.

Valence band electronic structure of carbon nitride from x-ray photoelectron spectroscopy

2002 ◽  
Vol 92 (1) ◽  
pp. 281-287 ◽  
Author(s):  
Z. Y. Chen ◽  
J. P. Zhao ◽  
T. Yano ◽  
T. Ooie
Keyword(s):  
Electronic Structure ◽  
Valence Band ◽  
Photoelectron Spectroscopy ◽  
Carbon Nitride ◽  
X Ray

scholarly journals Electronic structure and chemical bond nature in Cs2NpO2Cl4

2017 ◽  
Vol 32 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Yury Teterin ◽  
Konstantin Maslakov ◽  
Mikhail Ryzhkov ◽  
Anton Teterin ◽  
Kirill Ivanov ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Binding Energy ◽  
Energy Range ◽  
Valence Band ◽  
Chemical Bond ◽  
Photoelectron Spectroscopy ◽  
Theoretical Calculations ◽  
Molecular Orbitals ◽  
X Ray ◽  
Outer Valence

On the basis of the X-ray photoelectron spectroscopy data and results of theoretical calculations for the NpO2Cl4 (D4h) cluster, the electronic structure and the chemical bond nature in , was done in the binding Cs2NpO2Cl4 single crystal, containing the neptunyl group NpO2 energy range of 0 eV to ~35 eV. The filled Np 5f electronic states were established to form in the valence band of Cs2NpO2Cl4. This was attributed to the direct participation of the Np 5f electrons in the chemical bonding. The Np 6p electrons were shown to participate in formation of both the inner valence band (~15 eV-~35 eV) and the outer valence band (0 eV-~15 eV). The filled Np 6p and the O 2s, Cl 3s electronic shells were found to make the largest contribution to the formation of the inner valence molecular orbitals. The molecular orbitals composition and the sequence order in the binding energy range 0 eV-~35 eV in Cs2NpO2Cl4, were established. For the first time the quantitative scheme of molecular orbitals for the NpO2Cl4 cluster in the binding energy range 0 eV-~35 eV, was built. This scheme reflects neptunium close environment in the studied compound and is fundamental for both understanding the chemical bond nature in Cs2NpO2Cl4 and the interpretation of other X-ray spectra of Cs2NpO2Cl4. The contributions to the chemical binding for the NpO2Cl4 cluster were evaluated to be: the outer valence molecular orbitals contribution - 73 %, and the inner valence molecular orbitals contribution - 27 %.

XPS Spectra and Optical Reflectivity of Yttrium Stabilised Zirconia

1992 ◽  
Vol 293 ◽  
Author(s):  
P. Camagni ◽  
L.E. Depero ◽  
F. Parmigiani ◽  
G. Samoggia ◽  
L. Sangaletri ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Synchrotron Radiation ◽  
Energy Range ◽  
Single Crystals ◽  
Valence Band ◽  
Conduction Band ◽  
Photoelectron Spectroscopy ◽  
Electron Excitation ◽  
Xps Spectra ◽  
X Ray

AbstractX-ray photoelectron spectroscopy measurements and synchrotron radiation reflectivity and measurements in the photon energy range between 5eV and 30 eV are reported for yttrium stabilised zirconia single crystals. From the present data some behaviour of the valence band and conduction band electronic structure are elucidated. Two features present in the valence band XPS spectra, not explained on the basis of one-clectron theory, are tentatively assigned to simultaneous two electron excitation.

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