Study of Adsorption Properties of O2, CO2, NO2 and SO2 on Si-Doped Carbon Nanotube Using Density Functional Theory

2011 ◽  
Vol 110-116 ◽  
pp. 315-320
Author(s):  
M. R. Sonawane ◽  
B. J. Nagare
Keyword(s):  
Density Functional Theory ◽  
Charge Transfer ◽  
Carbon Nanotube ◽  
Binding Energy ◽  
Density Of States ◽  
Density Functional ◽  
Population Analysis ◽  
Energy Charge ◽  
Basis Set ◽  
Functional Theory

We report reactivity of silicon doped single walled carbon nanotube (Si-CNT) towards the small atmospheric gas molecules O2, CO2, SO2and NO2using density functional theory based on the numerical basis set method. The reactivity of these molecules is explained on the basis of electronic properties such as binding energy, charge density, charge transfer and density of states. The large change in binding energy and formation of sigma (σ) bonds between silicon and oxygen atoms shows the strong chemisorption of the molecules on Si-CNT. Further, the density of states analysis clearly illustrate the reduction in the band gap and creation of extra state near the Fermi level, which acts as a catalytic center for adsorption of the molecules. The Mulliken population analysis indicates the charge transfer from Si-CNT to the molecules due to their more electronegativity.

Na2M2(SO4)3 (M = Fe, Mn, Co and Ni): towards high-voltage sodium battery applications

2016 ◽  
Vol 18 (14) ◽  
pp. 9658-9665 ◽  
Author(s):  
Rafael B. Araujo ◽  
Sudip Chakraborty ◽  
Prabeer Barpanda ◽  
Rajeev Ahuja
Keyword(s):  
Crystal Structure ◽  
Density Functional Theory ◽  
Charge Transfer ◽  
Redox Potential ◽  
Density Of States ◽  
High Voltage ◽  
Density Functional ◽  
Structure Evolution ◽  
Sodium Ions ◽  
Functional Theory

We have employed density functional theory to systematically investigate the crystal structure evolution, density of states and charge transfer with sodium ions insertion, and the corresponding average redox potential, for Na2M2(SO4)3 (M = Fe, Mn, Co and Ni).

scholarly journals Pt Cluster Modified h-BN for Gas Sensing and Adsorption of Dissolved Gases in Transformer Oil: A Density Functional Theory Study

Nanomaterials ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1746 ◽  
Author(s):  
Yingang Gui ◽  
Tao Li ◽  
Xin He ◽  
Zhuyu Ding ◽  
Pingan Yang
Keyword(s):  
Density Functional Theory ◽  
Density Of States ◽  
Density Functional ◽  
Hexagonal Boron Nitride ◽  
Energy Charge ◽  
Boron Nitride Nanotubes ◽  
Transformer Oil ◽  
Total Density ◽  
Functional Theory ◽  
Pt Cluster

Hexagonal-Boron nitride nanotubes (h-BN) decorated with transition metals have been widely studied due to their enhanced physicochemical properties. In this paper, Pt cluster-modified h-BN is proposed as a sensitive material for a novel gas sensor for the online malfunction monitoring of oil-immersed transformers. The inner oil is ultimately decomposed to various gases during the long-term use of oil-immersed transformers. Exposure to excessively high temperatures produces the alkanes CH4 and C2H6, whereas different degrees of discharge generate H2 and C2H2. Therefore, the identification of H2, CH4, and C2H2 gas efficiently measures the quality of transformers. Based on the density functional theory, the most stable h-BN doped with 1–4 Pt atoms is employed to simulate its adsorption performance and response behavior to these typical gases. The adsorption energy, charge transfer, total density of states, projected density of states, and orbital theory of these adsorption systems are analyzed and the results show high consistency. The adsorption ability for these decomposition components are ordered as follows: C2H2 > H2 > CH4. Pt cluster-modified h-BN shows good sensitivity to C2H2, H2, with decreasing conductivity in each system, but is insensitive to CH4 due to its weak physical sorption. The conductivity change of Ptn-h-BN is considerably larger upon H2 than that upon C2H2, but is negligible upon CH4. Our calculations suggest that Pt cluster modified h-BN can be employed in transformers to estimate their operation status.

scholarly journals Substitution Effects on the Optoelectronic Properties of Coumarin Derivatives

2019 ◽  
Vol 10 (1) ◽  
pp. 144
Author(s):  
Amit Kumar ◽  
Roberto Baccoli ◽  
Antonella Fais ◽  
Alberto Cincotti ◽  
Luca Pilia ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Binding Energy ◽  
Molecular Orbital ◽  
Density Functional ◽  
Optoelectronic Properties ◽  
Exciton Binding Energy ◽  
Basis Set ◽  
Substitution Effects ◽  
Coumarin Derivatives ◽  
Functional Theory

Coumarin derivatives have gathered major attention largely due to their versatile utility in a wide range of applications. In this framework, we report a comparative computational investigation on the optoelectronic properties of 3-phenylcoumarin and 3-heteroarylcoumarin derivatives established as enzyme inhibitors. Specifically, we concentrate on the variation in the optoelectronic characteristics for the hydroxyl group substitutions within the coumarin moiety. In order to realize our aims, all-electron density functional theory and time dependent density functional theory calculations were performed with a localized Gaussian basis-set matched with a hybrid exchange–correlation functionals. Molecular properties such as highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energies, vertical ionization (IEV) and electron affinity energies, absorption spectra, quasi-particle gap, and exciton binding energy values are examined. Furthermore, the influence of solvent on the optical properties of the molecules is considered. We found a good agreement between the experimental (8.72 eV) and calculated (8.71 eV) IEV energy values for coumarin. The computed exciton binding energy of the investigated molecules indicated their potential optoelectronics application.

Binding Energies of Organic Charge-Transfer Complexes Calculated by First-Principles Methods

1998 ◽  
Vol 63 (8) ◽  
pp. 1223-1244 ◽  
Author(s):  
Cordula Rauwolf ◽  
Achim Mehlhorn ◽  
Jürgen Fabian
Keyword(s):  
Density Functional Theory ◽  
Charge Transfer ◽  
Ground State ◽  
Density Functional ◽  
Binding Energies ◽  
Basis Set ◽  
Dispersion Energy ◽  
Functional Theory ◽  
Basis Set Superposition Error ◽  
Donor And Acceptor

Weak interactions between organic donor and acceptor molecules resulting in cofacially-stacked aggregates ("CT complexes") were studied by second-order many-body perturbation theory (MP2) and by gradient-corrected hybrid Hartree-Fock/density functional theory (B3LYP exchange-correlation functional). The complexes consist of tetrathiafulvalene (TTF) and related compounds and tetracyanoethylene (TCNE). Density functional theory (DFT) and MP2 molecular equilibrium geometries of the component structures are calculated by means of 6-31G*, 6-31G*(0.25), 6-31++G**, 6-31++G(3df,2p) and 6-311G** basis sets. Reliable molecular geometries are obtained for the donor and acceptor compounds considered. The geometries of the compounds were kept frozen in optimizing aggregate structures with respect to the intermolecular distance. The basis set superposition error (BSSE) was considered (counterpoise correction). According to the DFT and MP2 calculations laterally-displaced stacks are more stable than vertical stacks. The charge transfer from the donor to the acceptor is small in the ground state of the isolated complexes. The cp-corrected binding energies of TTF/TCNE amount to -1.7 and -6.3 kcal/mol at the DFT(B3LYP) and MP2(frozen) level of theory, respectively (6-31G* basis set). Larger binding energies were obtained by Hobza's 6-31G*(0.25) basis set. The larger MP2 binding energies suggest that the dispersion energy is underestimated or not considered by the B3LYP functional. The energy increases when S in TTF/TCNE is replaced by O or NH but decreases with substitution by Se. The charge-transferred complexes in the triplet state are favored in the vertical arrangement. Self-consistent-reaction-field (SCRF) calculations predicted a gain in binding energy with solvation for the ground-state complex. The ground-state charge transfer between the components is increased up to 0.8 e in polar solvents.

scholarly journals Study of Magnesium Diboride Clusters Using Hybrid Density Functional Theory

2008 ◽  
Vol 2008 ◽  
pp. 1-4 ◽  
Author(s):  
D. Rodríguez ◽  
D. Soto ◽  
E. Ramírez ◽  
A. Cruz ◽  
A. Santana ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Magnesium Diboride ◽  
Population Analysis ◽  
Equilibrium Structure ◽  
Basis Set ◽  
Hybrid Density Functional Theory ◽  
Functional Theory ◽  
Equilibrium Structures ◽  
Hybrid Density Functional

Using hybrid density functional theory and a relatively large basis set, the lowest energy equilibrium structure, vibrational spectrum, and natural orbital analysis were obtained for magnesium diboride clusters [(MgB2)x for x=1,2, and 3]. For comparison, boron clusters [Bx for x=2,4, and 6] were also considered. The MgB2 and (MgB2)2 showed equilibrium structures with the boron atoms in arrangements similar to what was obtained for pure boron atoms, whereas, for (MgB2)3 a different arrangement of boron was obtained. From the population analysis, large electron density in the boron atoms forming the clusters was observed.

scholarly journals Density Functional Theory Study of Substitution Effects on the Second-Order Nonlinear Optical Properties of Lindquist-Type Organo-Imido Polyoxometalates

Symmetry ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1636
Author(s):  
Emna Rtibi ◽  
Benoit Champagne
Keyword(s):  
Density Functional Theory ◽  
Excited State ◽  
Charge Transfer ◽  
Density Functional ◽  
Energy Charge ◽  
Substitution Effects ◽  
First Hyperpolarizability ◽  
Functional Theory ◽  
State Approximation ◽  
Donor And Acceptor

Density functional theory and time-dependent density functional theory have been enacted to investigate the effects of donor and acceptor on the first hyperpolarizability of Lindquist-type organo-imido polyoxometalates (POMs). These calculations employ a range-separated hybrid exchange-correlation functional (ωB97X-D), account for solvent effects using the implicit polarizable continuum model, and analyze the first hyperpolarizabilities by using the two-state approximation. They highlight the beneficial role of strong donors as well as of π-conjugated spacers (CH=CH rather than C≡C) on the first hyperpolarizabilities. Analysis based on the unit sphere representation confirms the one-dimensional push-pull π-conjugated character of the POMs substituted by donor groups and the corresponding value of the depolarization ratios close to 5. Furthermore, the use of the two-state approximation is demonstrated to be suitable for explaining the origin of the variations of the first hyperpolarizabilities as a function of the characteristics of a unique low-energy charge-transfer excited state and to attribute most of the first hyperpolarizability changes to the difference of dipole moment between the ground and that charge-transfer excited state.

scholarly journals Theoretical Study of the Effect of Different π Bridges Including an Azomethine Group in Triphenylamine-Based Dye for Dye-Sensitized Solar Cells

Molecules ◽  
2019 ◽  
Vol 24 (21) ◽  
pp. 3897 ◽  
Author(s):  
Tomás Delgado-Montiel ◽  
Rody Soto-Rojo ◽  
Jesús Baldenebro-López ◽  
Daniel Glossman-Mitnik
Keyword(s):  
Density Functional Theory ◽  
Solar Cells ◽  
Charge Transfer ◽  
Density Functional ◽  
Dye Sensitized Solar Cells ◽  
Basis Set ◽  
Azomethine Group ◽  
Functional Theory ◽  
Dye Sensitized ◽  
Sensitized Solar Cells

Ten molecules were theoretically calculated and studied through density functional theory with the M06 density functional and the 6-31G(d) basis set. The molecular systems have potential applications as sensitizers for dye-sensitized solar cells. Three molecules were taken from the literature, and seven are proposals inspired in the above, including the azomethine group in the π-bridge expecting a better charge transfer. These molecular structures are composed of triphenylamine (donor part); different combinations of azomethine, thiophene, and benzene derivatives (π-bridge); and cyanoacrylic acid (acceptor part). This study focused on the effect that the azomethine group caused on the π-bridge. Ground-state geometry optimization, the highest occupied molecular orbital, the lowest unoccupied molecular orbital, and their energy levels were obtained and analyzed. Absorption wavelengths, oscillator strengths, and electron transitions were obtained via time-dependent density functional theory using the M06-2X density functional and the 6-31G(d) basis set. The free energy of electron injection (ΔGinj) was calculated and analyzed. As an important part of this study, chemical reactivity parameters are discussed, such as chemical hardness, electrodonating power, electroaccepting power, and electrophilicity index. In conclusion, the inclusion of azomethine in the π-bridge improved the charge transfer and the electronic properties of triphenylamine-based dyes.

Theoretical Study on Adsorption and Doping of Pd Atom on Graphene

2014 ◽  
Vol 893 ◽  
pp. 15-18
Author(s):  
Liang Qiao ◽  
Xiao Ying Hu ◽  
Dong Mei Bi ◽  
Li Jun Zhao
Keyword(s):  
Density Functional Theory ◽  
Binding Energy ◽  
Density Of States ◽  
Strong Interaction ◽  
Density Functional ◽  
Theoretical Study ◽  
Charge Redistribution ◽  
Bridge Site ◽  
Mulliken Population ◽  
Functional Theory

The adsorption and doping of Pd atom on graphene have been investigated using density-functional theory. The structure, binding energy, Mulliken population, and density of states of Pd-graphene systems are calculated. For the adsorbed graphene, the bridge site is the most favorable adsorption site. The adsorbed and doped Pd atom can stay stably on graphene by donating their charges to graphene, resulting in the charge redistribution of graphene. After the Pd functionalization, the hybridization of states of Pd and C atoms can be observed, indicating strong interaction between them.

scholarly journals Doping of 3d Transition Metals o n Monolayer o f Graphene a nd Borophene

2022 ◽  
Vol 10 (5) ◽  
pp. 41-47
Author(s):  
Keshav Dev ◽  
◽  
Swasti Saxena ◽  
Ankit K Srivastava ◽  
B.S Bhadoria ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Binding Energy ◽  
Transition Metal ◽  
Density Of States ◽  
Density Functional ◽  
Dirac Cone ◽  
Functional Theory ◽  
Electron Doping ◽  
Atom Density ◽  
Valence Bands

We Study the doping of various metallic 3d transition metal (TM) atoms like iron (Fe), Cobalt (Co), Copper (Cu) and Nickel (Ni) on monolayer of the borophene and graphene. These 2D layers show energy dispersion and metalloid properties because its band gap is very less or near to zero. We explored borophene is semi-metallic with the titled Dirac cone and graphene is semi metallic whose conduction and valence bands meets at Dirac cone. We analyzed the adsorption of 3d transition metal (TM) on the 2D layers through density functional theory (DFT) based calculations. In this paper, we observed the most suitable and acceptable adsorption site for each adatom, and calculated the binding energy per atom, density of states and magnetic moment of resulting borophene and graphene-adatom system. Here, we find that Nickel (Ni) is perfect as electron doping and iron (Fe) is the most effective for magnetically doped borophene. In the case of graphene we find that Co is most suitable for magnetically doping and Cu is best for electron doping.

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