scholarly journals Insight into anomalous hydrogen adsorption on rare earth metal decorated on 2-dimensional hexagonal boron nitride: a density functional theory study

RSC Advances ◽  
2020 ◽  
Vol 10 (22) ◽  
pp. 12929-12940
Author(s):  
Shreeja Das ◽  
Saroj K. Nayak ◽  
Kisor K. Sahu
Keyword(s):  
Rare Earth ◽  
Boron Nitride ◽  
Density Functional ◽  
Hydrogen Adsorption ◽  
Hexagonal Boron Nitride ◽  
Earth Metal ◽  
Functional Theory ◽  
Hydrogen Molecules ◽  
Strong Adsorption ◽  
Insight Into

The central rare earth cerium atom and underlying apolar B–N bonds in two-dimensional hexagonal boron nitride facilitate a unique arrangement of hydrogen molecules which leads to fairly strong adsorption of eight hydrogen molecules per metal atom.

scholarly journals Electronic Properties of Hydrogenated Hexagonal Boron Nitride (h-BN): DFT Study

2019 ◽  
Vol 4 (2) ◽  
pp. 72-79
Author(s):  
B. Chettri ◽  
P. K. Patra ◽  
Sunita Srivastava ◽  
Lalhriatzuala ◽  
Lalthakimi Zadeng ◽  
...  
Keyword(s):  
Boron Nitride ◽  
Band Gap ◽  
Electronic Properties ◽  
Density Functional ◽  
Hydrogen Adsorption ◽  
Hexagonal Boron Nitride ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Generalized Gradient Approximation ◽  
The Density Functional Theory

In this work, we have constructed the hydrogenated hexagonal boron nitride (h-BN) by placing hydrogen atom at different surface sites. The possibility of hydrogen adsorption on the BN surface has been estimated by calculating the adsorption energy. The electronic properties were calculated for different hydrogenated BNs. The theoretical calculation was based on the Density Functional Theory (DFT). The electron-exchange energy was treated within the most conventional functional called generalized gradient approximation. The calculated band gap of pure BN is 3.80 eV. The adsorption of two H-atoms at two symmetrical sites of B and N sites reduces the band gap value to 3.5 eV. However, in all other combination the systems show dispersed band at the Fermi level exhibiting conducting behavior. Moreover, from the analysis of band structure and Density Of States we can conclude that, the hydrogenation tunes the band gap of hexagonal boron nitride.

Investigation, using density function theory, of coverage of the kaolinite (001) surface during hydrogen adsorption

Clay Minerals ◽  
2018 ◽  
Vol 53 (3) ◽  
pp. 393-402 ◽  
Author(s):  
Jian Zhao ◽  
Wei Gao ◽  
Zhi-Gang Tao ◽  
Hong-Yun Guo ◽  
Man-Chao He
Keyword(s):  
Density Functional ◽  
Hydrogen Adsorption ◽  
Function Theory ◽  
Lattice Relaxation ◽  
Electronic Density ◽  
Functional Theory ◽  
Adsorption Sites ◽  
Coverage Dependence ◽  
Hydrogen Molecules ◽  
Wide Range

ABSTRACTKaolinite can be used for many applications, including the underground storage of gases. Density functional theory was employed to investigate the adsorption of hydrogen molecules on the kaolinite (001) surface. The coverage dependence of the adsorption sites and energetics was studied systematically for a wide range of coverage, Θ (from 1/16 to 1 monolayer). The three-fold hollow site is the most stable, followed by the bridge, top-z and top sites. The adsorption energy of H2 decreased with increasing coverage, thus indicating the lower stability of surface adsorption due to the repulsion of neighbouring H2 molecules. The coverage has obvious effects on hydrogen adsorption. Other properties of the H2/kaolinite (001) system, including the lattice relaxation and changes of electronic density of states, were also studied and are discussed in detail.

Ti-coated BC2N nanotubes as hydrogen storage materials

2013 ◽  
Vol 91 (7) ◽  
pp. 598-604 ◽  
Author(s):  
Seifollah Jalili ◽  
Farzad Molani ◽  
Jeremy Schofield
Keyword(s):  
Dft Calculations ◽  
Density Functional ◽  
Hydrogen Adsorption ◽  
Molecular Form ◽  
Hydrogen Storage Materials ◽  
Hydrogen Atoms ◽  
Functional Theory ◽  
Adsorption Sites ◽  
Hydrogen Molecules ◽  
Bc2n Nanotubes

Density functional theory (DFT) calculations have been performed to investigate Ti adsorption on BC2N nanotubes and the hydrogen adsorption capacity of Ti-coated structures. Different adsorption sites have been examined for the Ti adatom, and it is found that the most stable structure has a configuration with alternating columns of carbon and boron–nitrogen hexagons. The DFT calculations indicate that an adsorbed Ti atom on a carbon hexagon can bind four hydrogen molecules in molecular form, while Ti atoms on boron–nitride hexagons can adsorb three hydrogen molecules and two hydrogen atoms. Based on the calculations, the gravimetric efficiency corresponding to decoration of 67% of six carbon rings with Ti adatoms is estimated to be 8 wt %. Computation of the charge transfer reveals that the Ti atom on BC2N is in a cationic state. In addition, Ti adsorption has a significant influence on the electronic structure of the nanotubes and allows for the conversion of nanotubes from semiconductors in the pristine state to conductors upon doping. The interactions between the nanotubes, the Ti atom and hydrogen molecules have also been analyzed using Dewar coordination and Kubas interactions.

scholarly journals A First-Principles Study on Titanium-Decorated Adsorbent for Hydrogen Storage

Energies ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6845
Author(s):  
Kai Ma ◽  
Erfei Lv ◽  
Di Zheng ◽  
Weichun Cui ◽  
Shuai Dong ◽  
...  
Keyword(s):  
Hydrogen Storage ◽  
Density Functional ◽  
Hydrogen Adsorption ◽  
Density Functional Theory Calculation ◽  
Partial Density ◽  
Ambient Conditions ◽  
Functional Theory ◽  
Hydrogen Molecules ◽  
Theory Calculation ◽  
Hydrogen Storage Medium

Based on density functional theory calculation, we screened suitable Ti-decorated carbon-based hydrogen adsorbent structures. The adsorption characteristics and adsorption mechanism of hydrogen molecules on the adsorbent were also discussed. The results indicated that Ti-decorated double vacancy (2 × 2) graphene cells seem to be an efficient material for hydrogen storage. Ti atoms are stably embedded on the double vacancy sites above and below the graphene plane, with binding energy higher than the cohesive energy of Ti. For both sides of Ti-decorated double vacancy graphene, up to six H2 molecules can be adsorbed around each Ti atom when the adsorption energy per molecule is −0.25 eV/H2, and the gravimetric hydrogen storage capacity is 6.67 wt.%. Partial density of states (PDOS) analysis showed that orbital hybridization occurs between the d orbital of the adsorbed Ti atom and p orbital of C atom in the graphene layer, while the bonding process is not obvious during hydrogen adsorption. We expect that Ti-decorated double vacancy graphene can be considered as a potential hydrogen storage medium under ambient conditions.

Solid State and Electronic Structure of Rare Earth Metal Intercalated Graphite from First-principles Theory

2007 ◽  
Vol 62 (7) ◽  
pp. 971-976 ◽  
Author(s):  
Chang-Ming Fang ◽  
Joseph Bauer ◽  
Jean-Yves Saillard ◽  
Jean-Francois Halet
Keyword(s):  
Rare Earth ◽  
First Principles ◽  
Density Functional ◽  
Rare Earth Metals ◽  
Earth Metal ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Intercalated Graphite ◽  
Generalized Gradient Approximation ◽  
Cohesive Energies

Abstract The structural arrangements of the graphite intercalates LnC6 (Ln = La, Ce, Nd and Yb) were investigated using Density Functional Theory (DFT) within the Generalized Gradient Approximation (GGA). The EuC6-type structure (AαAβ AαAβ AαA stacking) is slightly energetically preferred for La and Ce, whereas with the other rare earth metals almost the same cohesive energies are found for the three different atomic arrangements AαAαAαAαAαA. . ., AαAβ AαAβ AαA. . ., and AαAβ AγAαAβ A. . . A rather important charge transfer occurs from the metals to the carbon sheets, with the electrons partially occupying the bottom of the carbon π* band. As a consequence, a lengthening of the C-C bond lengths of ca. 0.02 Å is computed with respect to the C-C bonds in graphite. Two-dimensional metallic character is expected for LaC6 according to its band structure.

scholarly journals Covalent coupling via dehalogenation on Ni(111) supported boron nitride and graphene

2015 ◽  
Vol 51 (12) ◽  
pp. 2440-2443 ◽  
Author(s):  
Claudius Morchutt ◽  
Jonas Björk ◽  
Sören Krotzky ◽  
Rico Gutzler ◽  
Klaus Kern
Keyword(s):  
Density Functional Theory ◽  
Boron Nitride ◽  
Density Functional ◽  
Hexagonal Boron Nitride ◽  
Scanning Tunnelling Microscopy ◽  
Functional Theory ◽  
Covalent Coupling ◽  
Scanning Tunnelling ◽  
Tunnelling Microscopy

Polymerization of 1,3,5-tris(4-bromophenyl)benzene on graphene and hexagonal boron nitride is investigated by scanning tunnelling microscopy and density functional theory.

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