Immobile crystallization of radioactive iodide by redox transformation of a low crystalline copper phase

Chemosphere ◽  
2021 ◽  
pp. 132266
Author(s):  
Seung Yeop Lee ◽  
Hyo Jin Seo ◽  
Ha-Rim An ◽  
Jang-Soon Kwon
Keyword(s):  
Redox Transformation ◽  
Copper Phase ◽  
Low Crystalline

Electron Donation by Low-Crystalline Ba-La-Ce Oxygen-Deficient Composite Oxide Accumulating on Ru Nanoparticles for Ammonia Synthesis under Mild Conditions

2019 ◽  
Author(s):  
Katsutoshi Sato ◽  
Shin-ichiro Miyahara ◽  
Yuta Ogura ◽  
Kotoko Tsujimaru ◽  
Yuichiro Wada ◽  
...  
Keyword(s):  
Ammonia Synthesis ◽  
Bond Cleavage ◽  
Synthesis Process ◽  
Strong Electron ◽  
Mild Conditions ◽  
Ru Nanoparticles ◽  
Rate Determining Step ◽  
Highly Active ◽  
Composite Oxides ◽  
Low Crystalline

<p>To mitigate global problems related to energy and global warming, it is helpful to develop an ammonia synthesis process using catalysts that are highly active under mild conditions. Here we show that the ammonia synthesis activity of Ru/Ba/LaCeO<i><sub>x</sub></i> pre-reduced at 700 °C is the highest reported among oxide-supported Ru catalysts. Our results indicate that low crystalline oxygen-deficient composite oxides, which include Ba<sup>2+</sup>, Ce<sup>3+</sup> and La<sup>3+</sup>, with strong electron-donating ability, accumulate on Ru particles and thus promote N≡N bond cleavage, which is the rate determining step for ammonia synthesis.</p>

Electron Donation by Low-Crystalline Ba-La-Ce Oxygen-Deficient Composite Oxide Accumulating on Ru Nanoparticles for Ammonia Synthesis under Mild Conditions

2019 ◽  
Author(s):  
Katsutoshi Sato ◽  
Shin-ichiro Miyahara ◽  
Yuta Ogura ◽  
Kotoko Tsujimaru ◽  
Yuichiro Wada ◽  
...  
Keyword(s):  
Ammonia Synthesis ◽  
Bond Cleavage ◽  
Synthesis Process ◽  
Strong Electron ◽  
Mild Conditions ◽  
Ru Nanoparticles ◽  
Rate Determining Step ◽  
Highly Active ◽  
Composite Oxides ◽  
Low Crystalline

<p>To mitigate global problems related to energy and global warming, it is helpful to develop an ammonia synthesis process using catalysts that are highly active under mild conditions. Here we show that the ammonia synthesis activity of Ru/Ba/LaCeO<i><sub>x</sub></i> pre-reduced at 700 °C is the highest reported among oxide-supported Ru catalysts. Our results indicate that low crystalline oxygen-deficient composite oxides, which include Ba<sup>2+</sup>, Ce<sup>3+</sup> and La<sup>3+</sup>, with strong electron-donating ability, accumulate on Ru particles and thus promote N≡N bond cleavage, which is the rate determining step for ammonia synthesis.</p>

scholarly journals Defect structures of sodium and chloride co-substituted hydroxyapatite and its osseointegration capacity

2021 ◽  
Vol 56 (9) ◽  
pp. 5493-5508
Author(s):  
Dong Su Yoo ◽  
Jung Sang Cho ◽  
Yong-Chae Chung ◽  
Sang-Hoon Rhee
Keyword(s):  
Binding Energies ◽  
Dissolution Behavior ◽  
Total System ◽  
Carbonate Apatite ◽  
In Vivo Test ◽  
Co Substitution ◽  
Constituent Elements ◽  
Low Crystalline ◽  
Charged Point

AbstractA defect structure and osseointegration capacity of sodium and chloride co-substituted hydroxyapatite (NaClAp) were newly studied. The NaClAp was prepared by reacting H3PO4 and Ca(OH)2 with NaNO3 and NH4Cl followed by sintering; pure hydroxyapatite (HAp) was synthesized as a control. After sintering, the co-substitution of Ca and OH with Na and Cl, respectively, produced charged point defects at Ca and PO4 sites. Also, OH molecules partially adopted a head-on structure. The calculated total system energy of NaClAp was higher, whereas the binding energies between each constituent elements and system were lower than those of HAp. These results suggest that NaClAp was less stable than HAp, due to the formation of various defects by co-substitution of Na and Cl. Indeed, NaClAp exhibited higher dissolution behavior in simulated body fluid (SBF) compared with HAp. Accordingly, this increased the capability to produce low crystalline hydroxyl carbonate apatite, likely due to the increasing degree of apatite supersaturation in SBF. Besides, the NaClAp granules showed noticeable improvements in osseointegration capacity four weeks after in vivo test compared with HAp. Collectively, these results imply that the defects made by multiple ion substitutions are useful to increase osseointegration capacity of hydroxyapatite.

scholarly journals Microscopic study of zinc nanoparticles synthesised using thermosetting polymer

2019 ◽  
Vol 49 (1) ◽  
Author(s):  
Giriraj Tailor ◽  
Jyoti Chaudhay ◽  
Deepshikha Verma ◽  
Bhupendra Kr. Sarma
Keyword(s):  
Electron Microscope ◽  
Xrd Analysis ◽  
The Novel ◽  
X Ray Diffraction ◽  
Zinc Nanoparticles ◽  
Transmission Electron ◽  
Sem Study ◽  
Zinc Salts ◽  
Thermosetting Polymer ◽  
Low Crystalline

AbstractThe present study reports the novel synthesis of Zinc nanoparticles (Zn NPs) by thermal decomposition method and its characterisation by Scanning Electron Microscope (SEM), Transmission Electron Microscope (TEM), and X-ray Diffraction Measurements (XRD). Synthesis of Zn NPs was achieved by using thermosetting polymer and zinc salts as precursor. Zn NPs were obtained on calcination at 850 °C for 30 min. SEM study reveals that synthesized nanoparticles are spherical in shape. XRD analysis shows that the Zn NPs formed are low crystalline in nature.

Transformation of low crystalline ferrihydrite to α-Fe2O3 in the solid state

2007 ◽  
Vol 834-836 ◽  
pp. 454-460 ◽  
Author(s):  
M. Ristić ◽  
E. De Grave ◽  
S. Musić ◽  
S. Popović ◽  
Z. Orehovec
Keyword(s):  
Solid State ◽  
Low Crystalline
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