scholarly journals Evolution of reduction process from tungsten oxide to ultrafine tungsten powder via hydrogen

2021 ◽  
Vol 40 (1) ◽  
pp. 171-177
Author(s):  
Yue Wang ◽  
Ben Fu Long ◽  
Chun Yu Liu ◽  
Gao An Lin
Keyword(s):  
Surface Morphology ◽  
Tungsten Oxide ◽  
Tungsten Powder ◽  
Reduction Process ◽  
Chemical Vapor ◽  
Transition Process ◽  
Vapor Transport ◽  
Fibrous Structure ◽  
Chemical Vapor Transport ◽  
Oxide Particles

Abstract Herein, the evolution of reduction process of ultrafine tungsten powder in industrial conditions was investigated. The transition process of morphology and composition was examined via SEM, XRD, and calcination experiments. The results show that the reduction sequence of WO2.9 was WO2.9 → WO2.72 → WO2 → W on the surface, but WO2.9 → WO2 → W inside the oxide particles. With the aid of chemical vapor transport of WO x (OH) y , surface morphology transformed into rod-like, star-shaped cracking, floret, irregularly fibrous structure, and finally, spherical tungsten particles.

Effect of Cu during Non-Isothermal Hydrogen Reduction of MoO3

2007 ◽  
Vol 534-536 ◽  
pp. 1253-1256 ◽  
Author(s):  
Gil Su Kim ◽  
Dae Gun Kim ◽  
Sung Tag Oh ◽  
Myung Jin Suk ◽  
Young Do Kim
Keyword(s):  
Hydrogen Reduction ◽  
Reduction Process ◽  
Chemical Vapor ◽  
Nucleation Site ◽  
Vapor Transport ◽  
Chemical Vapor Transport ◽  
Isothermal Process ◽  
Reduction Processes ◽  
Oxide Powders ◽  
Humidity Change

The effect of Cu on the hydrogen reduction of molybdenum oxide powders was investigated by measuring the humidity change during a non-isothermal process of hydrogen reduction. The presence of Cu induced a shift in the reduction temperature and strongly affected the reduction processes of MoO3→Mo4O11→MoO2, which comprised the contained chemical vapor transport of MoOx(OH)2. This study suggests that the surface of the Cu grains acts as a nucleation site for the reduction of MoOx(OH)2 to MoO2 particles from MoO3 or Mo4O11 phases. Such an activated reduction process results in the deposition of metallic Mo and MoO2 particles on the surface of the Cu grains.

Multiple Donors in Zinc Oxide Substrates

2002 ◽  
Vol 719 ◽  
Author(s):  
K. Thonke ◽  
N. Kerwien ◽  
A. Wysmolek ◽  
M. Potemski ◽  
A. Waag ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Chemical Vapor ◽  
Binding Energies ◽  
Vapor Transport ◽  
Chemical Vapor Transport ◽  
Oxide Substrates ◽  
Multiple Donors ◽  
Major Donors ◽  
Available Zinc ◽  
Transport Technique

AbstractWe investigate by photoluminescence (PL) nominally undoped, commercially available Zinc Oxide substrates (from Eagle Picher) grown by seeded chemical vapor transport technique in order to identify residual donors and acceptors. In low temperature PL spectra the dominant emission comes from the decay of bound exciton lines at around 3.36 eV. Zeeman measurements allow the identification of the two strongest lines and some weaker lines in-between as donorrelated. From the associated two-electron satellite lines binding energies of the major donors of 48 meV and 55 meV, respectively, can be deduced.

In situ formation of highly exposed NiPS3 nanosheets on nickel foam as an efficient 3D electrocatalyst for overall water splitting

2021 ◽  
Author(s):  
Liang Fang ◽  
Yanping Xie ◽  
Peiyin Guo ◽  
Jingpei Zhu ◽  
Shuhui Xiao ◽  
...  
Keyword(s):  
Water Splitting ◽  
Nickel Foam ◽  
Chemical Vapor ◽  
Bifunctional Catalyst ◽  
Vapor Transport ◽  
Chemical Vapor Transport ◽  
Overall Water Splitting ◽  
One Step ◽  
Transport Method

Vertical NiPS3 nanosheets in situ grown on conducting nickel foam were fabricated by a facile one-step chemical vapor transport method and used as an efficient bifunctional catalyst for overall water splitting.

Chemical Vapor Transport of Ternary Indium Molybdates.

ChemInform ◽  
2005 ◽  
Vol 36 (44) ◽  
Author(s):  
Udo Steiner ◽  
Werner Reichelt
Keyword(s):  
Chemical Vapor ◽  
Vapor Transport ◽  
Chemical Vapor Transport
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