New anatase phase VTi2.6O7.2 ultrafine nanocrystals for high-performance rechargeable magnesium-based batteries

2018 ◽  
Vol 6 (28) ◽  
pp. 13901-13907 ◽  
Author(s):  
Jinzhi Sheng ◽  
Chen Peng ◽  
Siwen Yan ◽  
Guobin Zhang ◽  
Yalong Jiang ◽  
...  
Keyword(s):  
Solid Solution ◽  
High Performance ◽  
Anatase Phase ◽  
Substitutional Solid Solution

A new kind of VTi2.6O7.2 ultrafine nanocrystals is designed via constructing substitutional solid solution, and it exhibits improved Mg2+ and Li+ storage performances.

scholarly journals Coherent Precipitation and Strengthening in Compositionally Complex Alloys: A Review

Entropy ◽  
2018 ◽  
Vol 20 (11) ◽  
pp. 878 ◽  
Author(s):  
Qing Wang ◽  
Zhen Li ◽  
Shujie Pang ◽  
Xiaona Li ◽  
Chuang Dong ◽  
...  
Keyword(s):  
Solid Solution ◽  
High Performance ◽  
Particle Morphology ◽  
Precipitation Strengthening ◽  
Second Phase ◽  
High Entropy ◽  
Second Phase Particles ◽  
Alloy Strength ◽  
Solid Solution Matrix ◽  
The Relationship

High-performance conventional engineering materials (including Al alloys, Mg alloys, Cu alloys, stainless steels, Ni superalloys, etc.) and newly-developed high entropy alloys are all compositionally-complex alloys (CCAs). In these CCA systems, the second-phase particles are generally precipitated in their solid-solution matrix, in which the precipitates are diverse and can result in different strengthening effects. The present work aims at generalizing the precipitation behavior and precipitation strengthening in CCAs comprehensively. First of all, the morphology evolution of second-phase particles and precipitation strengthening mechanisms are introduced. Then, the precipitation behaviors in diverse CCA systems are illustrated, especially the coherent precipitation. The relationship between the particle morphology and strengthening effectiveness is discussed. It is addressed that the challenge in the future is to design the stable coherent microstructure in different solid-solution matrices, which will be the most effective approach for the enhancement of alloy strength.

Effects of hydrogen on the microstructure and microchemistry of Ti3Al – Nb intermetallics at high temperatures and high pressures

1996 ◽  
Vol 11 (9) ◽  
pp. 2186-2197 ◽  
Author(s):  
H. Z. Xiao ◽  
I. M. Robertson ◽  
H. K. Birnbaum
Keyword(s):  
Solid Solution ◽  
High Temperatures ◽  
High Pressures ◽  
Chemical Potential ◽  
Substitutional Solid Solution ◽  
Hydrogen Gas ◽  
Solid Solution Phase ◽  
Face Centered Cubic ◽  
Fine Grained ◽  
Surrounding Matrix

The microstructural and microchemical changes produced in a Ti–25Al–10Nb–3V–1Mo alloy (at. %) by charging at high temperatures in high pressures of hydrogen gas have been studied using transmission electron microscopy (TEM) and x-ray methods. Hydrides incorporating all of the substitutional solutes that formed during charging have a face-centered cubic (fcc) structure and exhibit either a plate or fine-grained morphology. With increasing hydrogen content, the size of the hydrides decreases and their microchemistry changes as they approach the stable binary hydride, TiH2. Rejection of substitutional solute elements from the hydride produces changes in the microchemistry, and consequently in the crystal structure, of the surrounding matrix. In alloys containing 50 at. % H, this solute redistribution results in the formation of an orthohombic substitutional solid solution phase containing increased levels of Nb. The driving force of this redistribution of solutes is the reduction in the chemical potential of the system as the amount of the most stable hydride, TiH2, forms. The hydrides reverted to a solid solution on annealing in vacuum at 1073 K, and the original microchemistry of the alloy was restored. Reversion from the hydride structure to the original α2 ordered DO19 structure proceeds via a disordered HCP phase.

Microstructure and Hydrogen Permeability of Duplex Phase M-ZrNi (M=V, Nb, Ta) Alloys

2006 ◽  
Vol 980 ◽  
Author(s):  
Kazuhiro Ishikawa ◽  
Naoshi Kasagami ◽  
Tomoyuki Takano ◽  
Kiyoshi Aoki
Keyword(s):  
Crystal Structure ◽  
Solid Solution ◽  
High Performance ◽  
Gas Flow ◽  
Hydrogen Permeation ◽  
Hydrogen Permeability ◽  
The Other ◽  
Cast State ◽  
X Ray ◽  
Scanning Electron

AbstractIn order to develop non-Pd based high performance hydrogen permeation alloys, microstructure, crystal structure and hydrogen permeability of duplex phase M-ZrNi (M=V and Ta) alloys were investigated using a scanning electron microscope, an X-ray diffractometer and a gas flow meter. These results were compared with those of Nb-ZrNi ones which have been previously published. The hydrogen permeation was impossible in the V-ZrNi alloys, because they were brittle in the as-cast state. On the other hand, duplex phase alloys consisting of the bcc-(Ta, Zr) solid solution and the orthorhombic ZrNi (Cmcm) intermetallic compound were formed and hydrogen permeable in the Ta-ZrNi system. The Ta40Zr30Ni30 alloy shows the highest value of hydrogen permeability of 4.1×10-8 [molH2m-1s-1Pa-0.5] at 673 K, which is three times higher than that of pure Pd.

scholarly journals Hydrothermal Synthesis of rGO-TiO2 Composites as High-Performance UV Photocatalysts for Ethylparaben Degradation

Catalysts ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 520 ◽  
Author(s):  
Miller Ruidíaz-Martínez ◽  
Miguel A. Álvarez ◽  
María Victoria López-Ramón ◽  
Guillermo Cruz-Quesada ◽  
José Rivera-Utrilla ◽  
...  
Keyword(s):  
High Performance ◽  
Photocatalytic Performance ◽  
Raw Materials ◽  
Anatase Phase ◽  
Titanium Isopropoxide ◽  
Rutile Phase ◽  
Pure Tio2 ◽  
New Materials ◽  
Reduced Graphene ◽  
Structural Surface

A series of reduced graphene oxide-TiO2 composites (rGO-TiO2) were prepared by hydrothermal treatment using graphite and titanium isopropoxide as raw materials. The structural, surface, electronic, and optical properties of the prepared composites were extensively characterized by N2 adsorption, FTIR, XRD, XPS, Raman spectroscopy, and DRS. GO was found to be effectively reduced and TiO2 to be in pure anatase phase in all composites obtained. Finally, experiments were performed to evaluate the effectiveness of these new materials as photocatalysts in the degradation of ethylparaben (EtP) by UV radiation. According to the band-gap energies obtained (ranging between 3.09 eV for 4% rGO-TiO2 to 2.55 eV for 30% rGO-TiO2), the rGO-TiO2 composites behave as semiconductor materials. The photocatalytic activity is highest with a rGO content of 7 wt% (7% rGO-TiO2), being higher than observed for pure TiO2 (Eg = 3.20 eV) and achieving 98.6% EtP degradation after only 40 min of treatment. However, the degradation yield decreases with higher percentages of rGO. Comparison with rGO-P25 composites showed that a better photocatalytic performance in EtP degradation is obtained with synthesized TiO2 (rGO-TiO2), probably due to the presence of the rutile phase (14.1 wt %) in commercial P25.

Convenient synthesis of TiO2 nanowires with anatase phase for high photocatalytic activity

2020 ◽  
Vol 10 (4) ◽  
pp. 537-542
Author(s):  
Fei Tian ◽  
Gen Zhu ◽  
Kexin Shen ◽  
Chunju Li ◽  
Haitao Li ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
High Performance ◽  
Anatase Phase ◽  
Environmental Pollutants ◽  
High Photocatalytic Activity ◽  
Solar Irradiation ◽  
Tio2 Nanowires ◽  
Convenient Synthesis ◽  
Different Temperatures ◽  
Important Field

Organic pollutants pose a serious threat to human health, and so their control by photocatalytic techniques has become an important field. There is an urgent need to devise convenient syntheses of effective photocatalysts for the degradation of contaminants. Here, high-performance anatase TiO2 nanowires have been obtained through a hydrothermal method followed by calcination at different temperatures in Ar. The products have been characterized by SEM, XRD, FTIR, and UV/Vis DRS measurements. The photocatalytic performances of the as-prepared catalysts in the degradation of rhodamine 6G (R6G) have been evaluated. The experimental results revealed that as-prepared TiO2 nanowires calcined at 600 °C (TNWs-600) exhibited the highest degree of R6G degradation (96%) under simulated solar irradiation. This could be attributed to their stable anatase phase with good photocatalytic activity, the excellent light absorption ability of which favors excitation. Overall, the fabricated TNWs-600 constitute a promising candidate material for photocatalytic applications in the removal of environmental pollutants.

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