Hydrogen Absorption Kinetics and Mechanisms of Rare Earths (La, Ce, Pr, Nd, Tb, Dy) in the H2O Surface Reaction at Room Temperature.

ChemInform ◽  
2006 ◽  
Vol 37 (19) ◽  
Author(s):  
Hirohisa Uchida ◽  
Shunsuke Kato
Keyword(s):  
Rare Earths ◽  
Hydrogen Absorption ◽  
Room Temperature ◽  
Surface Reaction ◽  
Absorption Kinetics

A co-precipitated Mg–Ti nano-composite with high capacity and rapid hydrogen absorption kinetics at room temperature

RSC Advances ◽  
2014 ◽  
Vol 4 (81) ◽  
pp. 42764-42771 ◽  
Author(s):  
Yana Liu ◽  
Jinxin Zou ◽  
Xiaoqin Zeng ◽  
Wenjiang Ding
Keyword(s):  
Hydrogen Absorption ◽  
Room Temperature ◽  
High Capacity ◽  
Absorption Kinetics ◽  
Nano Composite

A Mg–Ti nano-composite was co-precipitated through an adapted Rieke method, which exhibits high capacity and superior absorption kinetics at room temperature (∼6.2 wt% within 2 h).

Redox-Inactive CO2 Determines Atmospheric Stability of Electrical Properties of ZnO Nanowire Devices through a Room-Temperature Surface Reaction

2019 ◽  
Vol 11 (43) ◽  
pp. 40260-40266
Author(s):  
Kentaro Nakamura ◽  
Tsunaki Takahashi ◽  
Takuro Hosomi ◽  
Takehito Seki ◽  
Masaki Kanai ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Room Temperature ◽  
Surface Reaction ◽  
Atmospheric Stability ◽  
Zno Nanowire ◽  
Temperature Surface

Room Temperature Hydrogen Absorption of Mg/MgH2 Catalyzed by BaTiO3

2021 ◽  
Author(s):  
Joshua Adedeji Bolarin ◽  
Zhao Zhang ◽  
Hujun Cao ◽  
Zhi Li ◽  
Teng He ◽  
...  
Keyword(s):  
Hydrogen Absorption ◽  
Room Temperature

scholarly journals Rare earths (Ce, Eu) molar concentration-dependent of the structural and optical properties of CBD-CdS nanofilms

2018 ◽  
Vol 64 (3) ◽  
pp. 240 ◽  
Author(s):  
Joel Diaz-Reyes ◽  
Jorge Indalecio Contreras-Rascón ◽  
Mariana Enelia Linares-Avilés ◽  
José Francisco Sánchez-Ramírez ◽  
José Eladio Flores-Mena ◽  
...  
Keyword(s):  
Raman Scattering ◽  
Rare Earths ◽  
Room Temperature ◽  
Longitudinal Mode ◽  
Radiative Transition ◽  
Molar Concentration ◽  
Raman Shift ◽  
Interstitial Oxygen ◽  
Synthesis Time ◽  
X Ray

It presents the characterization of rare earths (Eu,Ce)-doped CdS nanofilms that were synthesised by the growth technique chemical bath deposition (CBD) at the reservoir temperature of 70±2°C. The doping of CdS with rare earths is performed by varying the synthesis time from 60 to 135 min. The rare earths molar concentration was range from 0.0≤x≤3.5, which was determined by energy dispersive X-ray spectroscopy. X-ray diffraction (XRD) analysis and Raman scattering reveal that CdS nanofilms showed the zinc blende (ZB) crystalline phase. The CdS average nanocrystal size was ranged from 1.84 to 2.67 nm that was determined by the Debye–Scherrer equation from ZB (111) direction, which was confirmed by transmission electron microscopy. Raman scattering shows that the lattice dynamics is characteristic of bimodal behaviour and the multipeaks adjust of the first optical longitudinal mode for the (Eu,Ce)-doped CdS, which denotes the Raman shift of the characteristic peak about 305 cm−1 of the CdS nanocrystals. The CdS nanofilms exhibit a direct bandgap that slightly decreases with increasing doping, from 2.50 to 2.42 eV, which was obtained by room temperature transmittance. The room-temperature photoluminescence of CdS shows the band-to-band transition at 2.88 eV, which is associated to quantum confinement and a dominant radiative band at 2.37 eV that is called the optical signature of interstitial oxygen. The Eu3+-doped CdS photoluminescence shows the dominant radiative band at 2.15 eV, which is associated to the intra-4f radiative transition of Eu3+ ions that corresponds to the magnetic dipole transition, (5D0→7F1). For the Ce3+-doped CdS the dominant radiative transition, at 2.06 eV, is clearly redshifted, although the passivation of the CdS nanofilms by Ce was approximately by a factor about 21 for the best results.

Synthesis by High-Energy Ball Milling of MgH2-TiFe Composites for Hydrogen Storage

2017 ◽  
Vol 899 ◽  
pp. 13-18 ◽  
Author(s):  
Ricardo Mendes Leal Neto ◽  
Rafael de Araújo Silva ◽  
Ricardo Floriano ◽  
Graziele Cristina Seco Coutinho ◽  
Railson Bolsoni Falcão ◽  
...  
Keyword(s):  
Ball Milling ◽  
Hydrogen Absorption ◽  
Hydrogen Desorption ◽  
High Energy ◽  
Control Agent ◽  
High Energy Ball Milling ◽  
Absorption Kinetics ◽  
Particle Size Reduction ◽  
Milled Sample ◽  
Energy Ball

The aim of this work is to investigate the influence of some processes variables on the microstructure and hydrogen absorption kinetics of MgH2 - X wt.% TiFe composites. Samples were synthesized by high-energy ball milling in a planetary (X = 40, 50, 60) and shaker mill (X = 40) under high-purity argon atmosphere. Commercial MgH2 instead of Mg powder was used in order to reduce adherence on the vial and balls. TiFe powder was previously produced by ball milling a mixture of TiH2 and Fe powders followed by a reaction synthesis at 600oC. Milled composites samples were characterized by XRD and SEM analysis. Milling time was preliminary investigated (X = 40) in the planetary ball mill (6 to 36h). TiFe particle size reduction was shown to be difficult since they are surrounded by MgH2 matrix. Strong particle reduction was obtained by using a shaker mill only for 2 hours and adding cyclohexane as process control agent. No reaction between MgH2 and TiFe compound was observed in any milled sample. Hydrogen absorption kinetics measurements of the as-milled samples were conducted on an Sieverts' type apparatus at room temperature after hydrogen desorption at 350oC under vacuum. The best hydrogen kinetics (3 wt% at the first hour) was attained by the planetary milled sample (36 h). Higher hydrogen capacity was observed for the sample milled in the shaker mill (4.0 wt.%), but only after 13h.

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