scholarly journals An Insight into the Efficient Dimethoate Adsorption on Graphene-Based Materials—A Combined Experimental and DFT Study

2021 ◽  
Vol 11 (9) ◽  
pp. 4014
Author(s):  
Vladan J. Anićijević ◽  
Tamara D. Lazarević-Pašti ◽  
Vesna M. Vasić ◽  
Dragana D. Vasić Anićijević
Keyword(s):  
Density Functional ◽  
Dissociative Adsorption ◽  
Experimental Results ◽  
Hazardous Substances ◽  
Functional Theory ◽  
Basic Principles ◽  
Adsorption Sites ◽  
Defect Sites ◽  
Level 3 ◽  
Vacancy Type Defect

(1) Background: The development of highly efficient methods for removing hazardous substances from the environment attracts increasing attention. Understanding the basic principles of the removal processes using graphene materials is equally essential to confirm their application efficiency and safety. (2) Methods: In this contribution, adsorption of pesticide dimethoate (DMT) on graphene-based materials has been investigated on the molecular level. (3) Results: The experimental results’ analysis revealed a cooperative binding mechanism of the DMT on the adsorption sites of investigated materials—graphene oxide (GO) and industrial graphene (IG). The adsorption data were analyzed using various adsorption isotherms to determine the thermodynamics of the adsorption process. The experimental results were correlated with Density Functional Theory (DFT) calculations of DMT adsorption on the model surfaces that appropriately describe the graphene materials’ reactive features. (4) Conclusions: Considering experimental results, calculated adsorption energies, optimized adsorption geometries, and electronic structure, it was proposed that the dispersive interactions determine the adsorption properties of DMT on plain graphene sites (physisorption). Additionally, it was shown that the existence of vacancy-type defect sites on the surfaces could induce strong and dissociative adsorption (chemisorption) of DMT.

Adsorption and dissociation of O2 on MoSe2 and MoTe2 monolayers: ab initio study

2014 ◽  
Vol 28 (28) ◽  
pp. 1450195 ◽  
Author(s):  
X. F. Zhu ◽  
L. Wang ◽  
L. F. Chen
Keyword(s):  
Spin Polarization ◽  
Density Functional ◽  
Dissociative Adsorption ◽  
Generalized Gradient ◽  
Long Distance ◽  
Electronic Density ◽  
Functional Theory ◽  
Adsorption Sites ◽  
D Orbitals ◽  
Adsorption And Dissociation

Adsorption and dissociation of O 2 molecule on the MoSe 2 and MoTe 2 monolayers are studied by using density functional theory (DFT) within the generalized gradient approximation (GGA) and a supercell approach. The physisorbed O 2 molecule on MoSe 2 and MoTe 2 with a magnetic moment (MM) close to that for an isolated O 2 molecule has small adsorption energy and long distance from the surface. The dissociative adsorption of configuration R5(R6) is the most stable adsorption site, whereas the chemisorption of O 2 is unfavorable at all adsorption sites. The dissociative adsorption of configuration R4 induces dramatic changes of electronic structures and localized spin polarization both for monolayer MoSe 2 and MoTe 2. The analysis of electronic density of states (DOSs) shows that the contribution of spin polarization is mainly from the hybridization between O –p, Se(Te) –p and Mo –d orbitals.

The Damping Term, from First Principles

2017 ◽  
Author(s):  
Olle Eriksson ◽  
Anders Bergman ◽  
Lars Bergqvist ◽  
Johan Hellsvik
Keyword(s):  
Density Functional Theory ◽  
First Principles ◽  
Density Functional ◽  
Spin Dynamics ◽  
Damping Term ◽  
Functional Theory ◽  
Basic Principles ◽  
Sham Equation ◽  
Damping Parameter ◽  
Simulation Cell

In the previous chapters we described the basic principles of density functional theory, gave examples of how accurate it is to describe static magnetic properties in general, and derived from this basis the master equation for atomistic spin-dynamics; the SLL (or SLLG) equation. However, one term was not described in these chapters, namely the damping parameter. This parameter is a crucial one in the SLL (or SLLG) equation, since it allows for energy and angular momentum to dissipate from the simulation cell. The damping parameter can be evaluated from density functional theory, and the Kohn-Sham equation, and it is possible to determine its value experimentally. This chapter covers in detail the theoretical aspects of how to calculate theoretically the damping parameter. Chapter 8 is focused, among other things, on the experimental detection of the damping, using ferromagnetic resonance.

Density functional theory study into H2O dissociative adsorption on the Fe5C2(010) surface

2013 ◽  
Vol 468 ◽  
pp. 370-383 ◽  
Author(s):  
Rui Gao ◽  
Dong-Bo Cao ◽  
Shaoli Liu ◽  
Yong Yang ◽  
Yong-Wang Li ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Dissociative Adsorption ◽  
Density Functional Theory Study ◽  
Functional Theory

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.

scholarly journals Practical and Theoretical Study on the Inhibitory Influences of New Azomethine Derivatives Containing an 8-Hydroxyquinoline Moiety for the Corrosion of Carbon Steel in 1 M HCl

2018 ◽  
Vol 34 (6) ◽  
pp. 3016-3029 ◽  
Author(s):  
A. El-Yaktini ◽  
A. Lachiri ◽  
M. El-Faydy ◽  
F. Benhiba ◽  
H. Zarrok ◽  
...  
Keyword(s):  
Carbon Steel ◽  
Density Functional ◽  
Electrochemical Impedance ◽  
Density Functional Theory Method ◽  
Steel Corrosion ◽  
Experimental Results ◽  
Chemical Parameters ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Inhibition Ability

The inhibition ability of a new Azomethine derivatives containing the 8-hydroxyquinoline (BDHQ and MDHQ) towards carbon steel corrosion in HCl solution was studied at various concentrations and temperatures using weight loss, polarization curves and electrochemical impedance spectroscopy (EIS) methods. The experimental results reveal that BDHQ and MDHQ are efficient mixed type corrosion inhibitors, and their inhibition efficiencies increase with increasing concentration. The adsorption of these inhibitors on mild steel surface obeys Langmuir isotherm. Quantum chemical parameters are calculated using the Density Functional Theory method (DFT) and Monte Carlo simulations. Correlation between theoretical and experimental results is discussed.

ADSORPTION SITES OF THE PRODUCTS OF GeH4 ON ASYMMETRIC Si(100)(2×1) SURFACE

2004 ◽  
Vol 18 (08) ◽  
pp. 1191-1202
Author(s):  
ŞENAY KATıRCıOĞLU
Keyword(s):  
Density Functional ◽  
Geometry Optimization ◽  
Density Functional Theory Method ◽  
Adsorption Model ◽  
Functional Theory ◽  
Adsorption Models ◽  
Adsorption Sites ◽  
Asymmetric Dimer ◽  
Adsorption Energies ◽  
Relative Adsorption

The decomposition of GeH 4 on Si (100)(2×1) was investigated on different adsorption models of fragments using density functional theory method. The most probable adsorption model of fragments corresponding to the growth steps of SiGe film has been obtained by geometry optimization and single value total energy calculations. The relative adsorption energies of GeH 3, GeH 2 and GeH have been found to be -5.6, -5.1, and -4.5 eV for their most probable adsorption models respectively. It has been found that, the asymmetric dimer bond rows of Ge on Si (100) surface can be constructed by following the adsorption models corresponding to the relative adsorption energies of GeH 3, GeH 2 and GeH .

A Theoretical Study of H2S Toxic Gas Adsorption on Pristine and Doped Monolayer (AlN)21 Using Density Functional Theory

2020 ◽  
Vol 12 (02) ◽  
pp. 99-111
Author(s):  
Jamal A. Shlaka ◽  
◽  
Abbas H. Abo Nasria
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Theoretical Study ◽  
Gas Adsorption ◽  
Aluminium Nitride ◽  
Functional Theory ◽  
Adsorption Sites ◽  
Gas Molecules ◽  
Toxic Gas ◽  
Center Ring

Been studying the interactions between graphene - like aluminium nitride P(AlN)21 nano ribbons doped and defect (AlN)21Sheet, Molecules and small toxic gas molecules ( H2S), were built for two different adsorption sites on graphene like aluminium nitride P(AlN)21. this was done by employing B3LYP density functional theory (DFT) with 6-31G*(d,p) using Gaussian 09 program, Gaussian viw5.0 package of programs and Nanotube Modeller program 2018. the adsorptions of H2S on P(AlN)21, (C) atoms-doped P(AL-N)20 sheet, D-P(AL-N)20 and D-(C)atoms-doped P(AL-N)19 (on atom) with (Ead) (-0.468eV),(-0.473 eV), (-0.457 eV), (-0.4478 eV) and (-0.454 eV), respectively, (Ead) of H2S on the center ring of the P(AL-N)21, (C) atoms-doped P(AL-N)20 sheet, D-P(AL-N)20 and D-(C,B)atoms-doped P(AL-N)19 sheet are (-0.280 eV),(-0.465 eV), (-0.405 eV), (-0.468 eV) and -0.282 eV), respectively, are weak physisorption . However, the adsorptions of H2S, on the ((AlN)20 -B and D- (AlN)19 -B), (on atom N and center ring the sheet) are a strong chemisorption because of the (Ead) larger than -0.5 eV, due to the strong interaction, the ((AlN)20-B and D-(AlN)19-B), could catalyst or activate, through the results that we obtained, which are the improvement of the sheet P(AlN)21 by doping and per forming a defect in, it that can be used to design sensors. DOI: http://dx.doi.org/10.31257/2018/JKP/2020/120210

scholarly journals Adsorption of iron tetraphenylporphyrin on (111) surfaces of coinage metals: a density functional theory study

2017 ◽  
Vol 8 ◽  
pp. 2484-2491 ◽  
Author(s):  
Hao Tang ◽  
Nathalie Tarrat ◽  
Véronique Langlais ◽  
Yongfeng Wang
Keyword(s):  
Density Functional Theory ◽  
High Spin ◽  
Density Functional ◽  
Activation Barrier ◽  
High Spin State ◽  
Coulomb Repulsion ◽  
Functional Theory ◽  
Adsorption Sites ◽  
Intermediate Spin ◽  
Magnetic States

The adsorption of the iron tetraphenylporphyrin (FeTPP) molecule in its deckchair conformation was investigated on Au(111), Ag(111) and Cu(111) surfaces by performing spin-polarized density functional theory (DFT) calculations taking into account both van der Waals (vdW) interaction and on-site Coulomb repulsion. The deckchair conformation of the molecule favours intermolecular π–π-type interactions in a less densely packed monolayer than the saddle conformation. The activation barrier between the two stable magnetic states (high spin, S = 2 and intermediate spin, S = 1) of the molecule in vacuum disappears upon adsorption on the metal surfaces. The high-spin state of physisorbed FeTPP is stable on all adsorption sites. This result reveals that an external permanent element such as a STM tip or an additional molecule is needed to use FeTPP or similar molecules as model system for molecular spin switches.

Density functional theory calculations of hydrogen dissociative adsorption on platinum-involved alloy surfaces

2016 ◽  
Vol 306 ◽  
pp. 35-40 ◽  
Author(s):  
Kanchanok Kodchakorn ◽  
Vannajan Sanghiran Lee ◽  
Janchai Yana ◽  
Piyarat Nimmanpipug
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Dissociative Adsorption ◽  
Functional Theory

THEORETICAL STUDY OF NITROGEN MONOXIDE ADSORPTION ON RHODIUM CLUSTERS AT DIFFERENT SITES

2008 ◽  
Vol 07 (04) ◽  
pp. 669-679 ◽  
Author(s):  
JIAN CHEN ◽  
KAI TAN ◽  
MENG-HAI LIN
Keyword(s):  
Density Functional ◽  
Nitrogen Monoxide ◽  
Density Functional Theory Calculations ◽  
Frontier Orbitals ◽  
Functional Theory ◽  
Orbital Interactions ◽  
Adsorption Sites ◽  
Rhodium Clusters ◽  
Adsorption Of Nitrogen ◽  
Back Donation

The adsorption of nitrogen monoxide NO with charged and neutral [Formula: see text] clusters at atop, bridge, and threefold hollow sites had been investigated by density functional theory calculations. The results showed that rhodium clusters had strong orbital interactions with NO and formed the complex [ Rh n NO ]-/0/+. The stretching vibrational frequencies of the N–O bonds changed with the different adsorption sites and clusters sizes. The interactions between rhodium clusters and NO molecular could be described through the donation and back-donation of their frontier orbitals. The more back donation from Rh to NO , the weaker the N–O bonds, exhibiting that the lengthening of the N–O bond length and the lowering of its vibrational frequency. In general, the donation and back-donation interactions followed the tendencies: anionic > neutral > cationic, big size > small size, threefold hollow site > bridge site > atop site.

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