ChemInform Abstract: MOLECULAR NITROGEN AS A LIGAND, A STUDY OF DINITROGEN COMPLEXES OF TRANSITION METALS, DIAZOCOMPOUNDS, AND AZIDES BY X-RAY PHOTOELECTRON SPECTROSCOPY

1974 ◽  
Vol 5 (9) ◽  
pp. no-no
Author(s):  
V. I. NEFEDOV ◽  
V. S. LENENKO ◽  
V. B. SHUR ◽  
M. E. VOL'PIN ◽  
J. E. SALYN ◽  
...  
Keyword(s):  
Transition Metals ◽  
Photoelectron Spectroscopy ◽  
Molecular Nitrogen ◽  
X Ray ◽  
Dinitrogen Complexes ◽  
Complexes Of Transition Metals

HAFNIUM AND NITROGEN INTERACTION AT Hf/GaN(0001) INTERFACE

2020 ◽  
Vol 27 (11) ◽  
pp. 2050013
Author(s):  
RAFAŁ LEWANDKÓW ◽  
RADOSŁAW WASIELEWSKI ◽  
PIOTR MAZUR
Keyword(s):  
Thermal Treatment ◽  
Photoelectron Spectroscopy ◽  
Molecular Nitrogen ◽  
Native Oxide ◽  
Ultraviolet Photoelectron Spectroscopy ◽  
Atomic Nitrogen ◽  
Stable Layer ◽  
Xps Spectra ◽  
X Ray ◽  
Strong Shift

The growth and stability of hafnium films on [Formula: see text]-GaN(0001) surface with native oxide was investigated with X-ray and ultraviolet photoelectron spectroscopy (XPS, UPS). It is shown that hafnium creates a continuous and stable layer on GaN substrate. Thermal treatment at [Formula: see text]C of Hf/GaN system causes decomposition of GaN and reaction of hafnium with atomic nitrogen from the substrate. XPS spectra demonstrate the reaction by a strong shift of the N 1s and Hf 4f lines. An attempt for bringing on the same reaction with molecular nitrogen under pressure of [Formula: see text] mbar was not successful. UPS spectra show a metallic character of the hafnium adlayer in such instances.

scholarly journals Molecular nitrogen in N-doped TiO2 nanoribbons

RSC Advances ◽  
2015 ◽  
Vol 5 (30) ◽  
pp. 23350-23356 ◽  
Author(s):  
C. Bittencourt ◽  
M. Rutar ◽  
P. Umek ◽  
A. Mrzel ◽  
K. Vozel ◽  
...  
Keyword(s):  
Fine Structure ◽  
Photoelectron Spectroscopy ◽  
Nitrogen Doping ◽  
Molecular Nitrogen ◽  
Doped Tio2 ◽  
X Ray ◽  
Absorption Fine ◽  
X Ray Absorption

X-ray photoelectron spectroscopy (XPS) and near-edge X-ray absorption fine structure (NEXAFS) support the idea that during nitrogen doping of TiO2 nanoribbons N2 molecules may be formed and trapped in the nanostructures.

Third Row Transition Metals by X-ray Photoelectron Spectroscopy

2000 ◽  
Vol 7 (1) ◽  
pp. 1-68 ◽  
Author(s):  
Mark Engelhard ◽  
Don Baer
Keyword(s):  
Transition Metals ◽  
Photoelectron Spectroscopy ◽  
X Ray

scholarly journals Thermal CO Oxidation and Photocatalytic CO2 Reduction over Bare and M-Al2O3 (M = Co, Ni, Cu, Rh, Pd, Ag, Ir, Pt, and Au) Cotton-Like Nanosheets

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1278
Author(s):  
Heejung Yoon ◽  
Juhyun Yang ◽  
Sojeong Park ◽  
Youngku Sohn
Keyword(s):  
Electron Microscopy ◽  
Transition Metals ◽  
Co Oxidation ◽  
Photoelectron Spectroscopy ◽  
Co2 Reduction ◽  
Data Sets ◽  
X Ray Diffraction ◽  
Oxidation Activity ◽  
X Ray ◽  
Transmission Electron

Aluminum oxide (Al2O3) has abundantly been used as a catalyst, and its catalytic activity has been tailored by loading transition metals. Herein, γ-Al2O3 nanosheets were prepared by the solvothermal method, and transition metals (M = Co, Ni, Cu, Rh, Pd, Ag, Ir, Pt, and Au) were loaded onto the nanosheets. Big data sets of thermal CO oxidation and photocatalytic CO2 reduction activities were fully examined for the transition metal-loaded Al2O3 nanosheets. Their physicochemical properties were examined by scanning electron microscopy, high-resolution transmission electron microscopy, X-ray diffraction crystallography, and X-ray photoelectron spectroscopy. It was found that Rh, Pd, Ir, and Pt-loading showed a great enhancement in CO oxidation activity while other metals negated the activity of bare Al2O3 nanosheets. Rh-Al2O3 showed the lowest CO oxidation onset temperature of 172 °C, 201 °C lower than that of bare γ-Al2O3. CO2 reduction experiments were also performed to show that CO, CH3OH, and CH4 were common products. Ag-Al2O3 nanosheets showed the highest performances with yields of 237.3 ppm for CO, 36.3 ppm for CH3OH, and 30.9 ppm for CH4, 2.2×, 1.2×, and 1.6× enhancements, respectively, compared with those for bare Al2O3. Hydrogen production was found to be maximized to 20.7 ppm during CO2 reduction for Rh-loaded Al2O3. The present unique pre-screening test results provided very useful information for the selection of transition metals on Al2O3-based energy and environmental catalysts.

Systematic X-ray photoelectron spectroscopy and theoretical studies of disulfides of groups IVB, VB and VIB transition metals

1997 ◽  
Vol 83 (1) ◽  
pp. 45-58 ◽  
Author(s):  
K. Dartigeas ◽  
L. Benoist ◽  
D. Gonbeau ◽  
G. Pfister-Guillouzo ◽  
G. Ouvrard ◽  
...  
Keyword(s):  
Transition Metals ◽  
Photoelectron Spectroscopy ◽  
Theoretical Studies ◽  
X Ray

scholarly journals High-Entropy 2D Carbide MXenes

2021 ◽  
Author(s):  
Srinivasa Kartik Nemani ◽  
BOWEN ZHANG ◽  
Brian C. Wyatt ◽  
Zachary D. Hood ◽  
Sukriti Manna ◽  
...  
Keyword(s):  
Transition Metals ◽  
Photoelectron Spectroscopy ◽  
Single Phase ◽  
Configurational Entropy ◽  
Max Phase ◽  
High Temperature Stability ◽  
Max Phases ◽  
X Ray ◽  
High Entropy ◽  
Synthesis Conditions

<p>Two-dimensional (2D) transition metal carbides and nitrides, known as MXenes, are a fast-growing family of 2D materials. MXenes 2D flakes have <i>n </i>+ 1 (<i>n</i> = 1 – 4) atomic layers of transition metals interleaved by carbon/nitrogen layers, but to-date remain limited in composition to one or two transition metals. In this study, through the use of four transition metals, we report the synthesis of multi-principal element high-entropy M<sub>4</sub>C<sub>3</sub>T<i><sub>x</sub></i> MXenes. Specifically, we introduce two high-entropy MXenes, TiVNbMoC<sub>3</sub>T<i><sub>x</sub></i> and TiVCrMoC<sub>3</sub>T<i><sub>x</sub></i>, as well as their precursor TiVNbMoAlC<sub>3</sub> and TiVCrMoAlC<sub>3 </sub>high-entropy MAX phases. We used a combination of real and reciprocal space characterization (x-ray diffraction, x-ray photoelectron spectroscopy, energy dispersive x-ray spectroscopy, and scanning transmission electron microscopy) to establish the structure, phase purity, and equimolar distribution of the four transition metals in high-entropy MAX and MXene phases. We use first-principles calculations to compute the formation energies and explore synthesizability of these high-entropy MAX phases. We also show that when three transition metals are used instead of four, under similar synthesis conditions to those of the four-element MAX phase, two different MAX phases can be formed (<i>i.e.</i> no pure single-phase forms). This finding indicates the importance of configurational entropy in stabilizing the desired single-phase high-entropy MAX over multiphases of MAX, which is essential for the synthesis of phase-pure high-entropy MXenes. The synthesis of high-entropy MXenes significantly expand the compositional variety of the MXene family to further tune their properties, including electronic, magnetic, electrochemical, catalytic, high temperature stability, and mechanical properties. </p>

scholarly journals High-Entropy 2D Carbide MXenes

2021 ◽  
Author(s):  
Srinivasa Kartik Nemani ◽  
BOWEN ZHANG ◽  
Brian C. Wyatt ◽  
Zachary D. Hood ◽  
Sukriti Manna ◽  
...  
Keyword(s):  
Transition Metals ◽  
Photoelectron Spectroscopy ◽  
Single Phase ◽  
Configurational Entropy ◽  
Max Phase ◽  
High Temperature Stability ◽  
Max Phases ◽  
X Ray ◽  
High Entropy ◽  
Synthesis Conditions

<p>Two-dimensional (2D) transition metal carbides and nitrides, known as MXenes, are a fast-growing family of 2D materials. MXenes 2D flakes have <i>n </i>+ 1 (<i>n</i> = 1 – 4) atomic layers of transition metals interleaved by carbon/nitrogen layers, but to-date remain limited in composition to one or two transition metals. In this study, through the use of four transition metals, we report the synthesis of multi-principal element high-entropy M<sub>4</sub>C<sub>3</sub>T<i><sub>x</sub></i> MXenes. Specifically, we introduce two high-entropy MXenes, TiVNbMoC<sub>3</sub>T<i><sub>x</sub></i> and TiVCrMoC<sub>3</sub>T<i><sub>x</sub></i>, as well as their precursor TiVNbMoAlC<sub>3</sub> and TiVCrMoAlC<sub>3 </sub>high-entropy MAX phases. We used a combination of real and reciprocal space characterization (x-ray diffraction, x-ray photoelectron spectroscopy, energy dispersive x-ray spectroscopy, and scanning transmission electron microscopy) to establish the structure, phase purity, and equimolar distribution of the four transition metals in high-entropy MAX and MXene phases. We use first-principles calculations to compute the formation energies and explore synthesizability of these high-entropy MAX phases. We also show that when three transition metals are used instead of four, under similar synthesis conditions to those of the four-element MAX phase, two different MAX phases can be formed (<i>i.e.</i> no pure single-phase forms). This finding indicates the importance of configurational entropy in stabilizing the desired single-phase high-entropy MAX over multiphases of MAX, which is essential for the synthesis of phase-pure high-entropy MXenes. The synthesis of high-entropy MXenes significantly expand the compositional variety of the MXene family to further tune their properties, including electronic, magnetic, electrochemical, catalytic, high temperature stability, and mechanical properties. </p>

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