Hydrogen storage on palladium adsorbed graphene: A density functional theory study

2015 ◽  
Vol 29 (20) ◽  
pp. 1550143 ◽  
Author(s):  
Nurapati Pantha ◽  
Asim Khaniya ◽  
Narayan Prasad Adhikari

We have performed density functional theory (DFT)-based first-principles calculations to study the stability, geometrical structures, and electronic properties of a single palladium (Pd) atom adsorbed graphene with reference to pristine graphene. The study also covers the adsorption properties of molecular hydrogen/s on the most stable Pd-graphene geometry by taking into account London dispersion forces in addition to the standard DFT calculations in the Quantum ESPRESSO package. From the analysis of estimated values of binding energy of Pd on different occupation sites (i.e., bridge, hollow, and top) of graphene supercells, the bridge site is found to be the most favorable one with the magnitudes of 1.114, 1.426, and 1.433 eV in 2×2, 3×3, and 4×4 supercells, respectively. The study of the electronic properties of Pd adsorbed graphene shows a bandgap of 45 meV, which can account for the breaking of the symmetry of the graphene structure. Regarding the gaseous (hydrogen) adsorption on Pd-adatom graphene, we checked the increasing number of molecular hydrogens ( H 2) from one to seven on the 3×3 supercell, and found that the adsorption energy per H 2 decreases on increasing hydrogen concentration and lies within the range of 0.998–0.151 eV.

2016 ◽  
Vol 3 (1) ◽  
pp. 24 ◽  
Author(s):  
Bishnu Prasad Paudel ◽  
Nurapati Pantha ◽  
Narayan Prasad Adhikari

<p>The functionalization of graphene by the addition of Manganese (Mn) atom to its surface has been investigated computationally by using density-functional theory (DFT) based first-principles method within DFT-D2 level of approximations. The calculations have been computed employing the Quantum ESPRESSO codes. The stability, geometrical structures, electronic and magnetic properties of pure and Mn adatom graphene systems have been studied. From the information of adsorption energies of Mn atom on the different sites of graphene, the top site is found to be the most favorable one for its adsorption. Present study finds that the London dispersion interaction plays a major role in the weak binding of Mn on graphene. The study of electronic and magnetic properties of Mn decorated graphene shows that the conduction and valence band are overlapped with finite density of states (DOS) at Fermi level. The dissimilar DOS for up and down spin calculations quantify magnetic moment as 5.48 μ<sub>B</sub> which is consistent with the previous study</p><p>Journal of Nepal Physical Society Vol.3(1) 2015: 24-34</p>


2008 ◽  
Vol 07 (04) ◽  
pp. 505-515
Author(s):  
LIQIN XUE ◽  
GUOCHEN JIA ◽  
ZHENYANG LIN

The relative stability of the trans and cis isomers in the square planar palladium(II) complexes Pd ( I )( PPh 3)(η3- XCHC ( Ph ) CHR ) ( X = H , Me , CMe 3, CO 2 Me , P ( O )( OMe )2, and SO 2 H ; R = H , Me ) was investigated with the aid of the B3LYP density functional theory calculations. We examined how the substituents X, with different electronic properties, of the η3-allyl ligands affect the relative stability of the trans and cis isomers. Through the investigation, we were able to explain the trans/cis relative stability derived from the experimentally measured trans/cis isomer ratios in the palladium(II) complexes.


2019 ◽  
Vol 74 (2) ◽  
pp. 121-129 ◽  
Author(s):  
Ming Hui ◽  
Qing-Huai Zhao ◽  
Zhi-Peng Wang ◽  
Shuai Zhang ◽  
Gen-Quan Li

AbstractThe effects of halogen element X (X = Br, I) doping on the geometrical structures and electronic properties of neutral aluminium clusters are systematically studied by utilising the density functional theory calculations. The structures of X-doped clusters show the three-dimensional forms with increasing atomic number except for n = 3 and X (X = Br, I) atom prefer to occupy the surface site of the host Aln clusters. BrAl7 and IAl7 clusters are the most stable geometries. The HOMO-LUMO energy gap and chemical hardness show an odd–even alternative phenomenon. The charges always transfer from the Al atoms to the X (X = Br, I) atom. Finally, the dipole and polarisability are discussed.


BIBECHANA ◽  
2014 ◽  
Vol 11 ◽  
pp. 113-122 ◽  
Author(s):  
S Lamichhane ◽  
N Pantha ◽  
NP Adhikari

Adsorption of gaseous/molecular hydrogen on platinum (Pt) decorated and pristine graphene have been studied systematically by using density functional theory (DFT) level of calculations implemented by Quantum ESPRESSO codes. The Perdew-Burke-Ernzerhof (PBE) type generalized gradient approximation (GGA) exchange-correlation functional and London dispersion forces have been incorporated in the DFT-D2 level of algorithm for short and long range electron-electron interactions, respectively. With reference to the binding energy of Pt on different symmetry sites of graphene supercells, the bridge (B) site has been predicted as the best adsorption site. In case of 3×3 supercell of graphene (used for detail calculations), the binding energy has been estimated as 2.02 eV. The band structure and density of states calculations of Pt adatom graphene predict changes in electronic/magnetic properties caused by the atom (Pt). The adatom (Pt) also enhances the binding energy per hydrogen molecule in Pt-graphene comparing to that in pristine graphene and records the values within the range of 1.84 eV to 0.13 eV for one to eight molecules, respectively. DOI: http://dx.doi.org/10.3126/bibechana.v11i0.10389 BIBECHANA 11(1) (2014) 113-122


RSC Advances ◽  
2014 ◽  
Vol 4 (89) ◽  
pp. 48017-48021 ◽  
Author(s):  
Jun Dai ◽  
Xiao Cheng Zeng

We investigate the stability and electronic properties of oxy- (O) or imine- (NH) functionalized monolayer phosphorene with either single-side or double-side functionalization based on density-functional theory calculations.


RSC Advances ◽  
2018 ◽  
Vol 8 (44) ◽  
pp. 24847-24856 ◽  
Author(s):  
A. Freitas ◽  
L. D. Machado ◽  
C. G. Bezerra ◽  
R. M. Tromer ◽  
L. F. C. Pereira ◽  
...  

We combine density functional theory and molecular dynamics to investigate the stability and electronic properties of 20 structures composed of boron, carbon, and nitrogen arranged in the pattern of the two-dimensional carbon allotrope graphenylene.


2015 ◽  
Vol 17 (34) ◽  
pp. 22210-22216 ◽  
Author(s):  
Caroline J. Rupp ◽  
Sudip Chakraborty ◽  
Rajeev Ahuja ◽  
Rogério J. Baierle

Spin polarized density functional theory within the GGA–PBE and HSE06 approach for the exchange correlation term has been used to investigate the stability and electronic properties of nitrogen and boron impurities in single layers of silicane and germanane.


2011 ◽  
Vol 347-353 ◽  
pp. 3489-3492
Author(s):  
Li Bin Shi ◽  
Hong Kuan Yuan

Using the first principle method based on density functional theory (DFT), we have studied the stability, structure, and electronic properties in (2 2), (3, 3), (4 4), (5 5), (6 6) armchair and (4 0), (5 0), (6 0) zigzag GaN nanotubes (GaN-NTs). In addition, the radius of N, Ga atoms, buckling separations, band gap and binding energy of (3 3) and (4 0) GaN-NTs in c-axis strain are investigated. We also explore the modification of density of states due to the strain along c-axis orientation. It is found that the strain can change conductive properties of (3 3) and (4 0) GaN-NTs.


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