Al-doped graphene as an effective adsorber for some toxic derivatives of aromatic hydrocarbons

2017 ◽  
Vol 16 (01) ◽  
pp. 1750004 ◽  
Author(s):  
Min Ji ◽  
Xinlu Cheng ◽  
Weidong Wu
Keyword(s):  
Charge Transfer ◽  
Aromatic Hydrocarbons ◽  
Adsorption Energy ◽  
Density Functional ◽  
Hydroxyl Group ◽  
The Density Functional Theory ◽  
Doped Graphene ◽  
Perfect Graphene ◽  
Hydrocarbons Adsorption ◽  
Derivatives Of

The density functional theory (DFT) was used to investigate some toxic derivatives of aromatic hydrocarbons adsorption on perfect graphene (pG) and graphene-doped with B/Al/Ga (BG/AlG/GaG). And the parallel and vertical adsorptions were considered for the position relation between the adsorbent and adsorbate. The adsorption energy, adsorption distance, charge transfer and density of states (DOS) were discussed in optimized structures. The greater adsorption energy, shorter adsorption distance and more charge transfer were found in AlG by studying the four kinds of molecules (phenol/m-cresol/PCP/p-NP) adsorption on pG/BG/AlG/GaG. Then, 10 derivatives adsorption on AlG were reported, and the adsorption energy increased in the order of pentachlorophenol [Formula: see text] 2,4,6-trichlorophenol [Formula: see text] 2,4-dichlorophenol [Formula: see text] p-cresol [Formula: see text] m-cresol [Formula: see text] phenol [Formula: see text] o-chlorophenol [Formula: see text] o-cresol [Formula: see text] 2,4,6-trintrotoluene [Formula: see text] para-nitrophenol. The interaction between these derivatives and the substrate was chemisorption for AlG and physisorption for pG. The oxygen atom in nitro group was more closer to the substrate than in hydroxyl group about optimized structures.

scholarly journals CO2 Adsorption on PtCu Sub-Nanoclusters Deposited on Pyridinic N-Doped Graphene: A DFT Investigation

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7619
Author(s):  
Fernando Montejo-Alvaro ◽  
Diego González-Quijano ◽  
Jorge A. Valmont-Pineda ◽  
Hugo Rojas-Chávez ◽  
José M. Juárez-García ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Density Functional ◽  
Co2 Adsorption ◽  
Value Added ◽  
Co2 Concentration ◽  
Binding Energies ◽  
The Density Functional Theory ◽  
Doped Graphene ◽  
The Stability ◽  
Pyridinic N

To reduce the CO2 concentration in the atmosphere, its conversion to different value-added chemicals plays a very important role. Nevertheless, the stable nature of this molecule limits its conversion. Therefore, the design of highly efficient and selective catalysts for the conversion of CO2 to value-added chemicals is required. Hence, in this work, the CO2 adsorption on Pt4-xCux (x = 0–4) sub-nanoclusters deposited on pyridinic N-doped graphene (PNG) was studied using the density functional theory. First, the stability of Pt4-xCux (x = 0–4) sub-nanoclusters supported on PNG was analyzed. Subsequently, the CO2 adsorption on Pt4-xCux (x = 0–4) sub-nanoclusters deposited on PNG was computed. According to the binding energies of the Pt4-xCux (x = 0–4) sub-nanoclusters on PNG, it was observed that PNG is a good material to stabilize the Pt4-xCux (x = 0–4) sub-nanoclusters. In addition, charge transfer occurred from Pt4-xCux (x = 0–4) sub-nanoclusters to the PNG. When the CO2 molecule was adsorbed on the Pt4-xCux (x = 0–4) sub-nanoclusters supported on the PNG, the CO2 underwent a bond length elongation and variations in what bending angle is concerned. In addition, the charge transfer from Pt4-xCux (x = 0–4) sub-nanoclusters supported on PNG to the CO2 molecule was observed, which suggests the activation of the CO2 molecule. These results proved that Pt4-xCux (x = 0–4) sub-nanoclusters supported on PNG are adequate candidates for CO2 adsorption and activation.

scholarly journals Study on the interaction between catechin and cholesterol by the density functional theory

2020 ◽  
Vol 18 (1) ◽  
pp. 357-368
Author(s):  
Kaiwen Zheng ◽  
Kai Guo ◽  
Jing Xu ◽  
Wei Liu ◽  
Junlang Chen ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Hydrogen Bond ◽  
Charge Transfer ◽  
Density Functional ◽  
Antioxidant Properties ◽  
Micelle Formation ◽  
Aromatic Rings ◽  
Hydrogen Bond Interaction ◽  
Functional Theory ◽  
The Density Functional Theory

AbstractCatechin – a natural polyphenol substance – has excellent antioxidant properties for the treatment of diseases, especially for cholesterol lowering. Catechin can reduce cholesterol content in micelles by forming insoluble precipitation with cholesterol, thereby reducing the absorption of cholesterol in the intestine. In this study, to better understand the molecular mechanism of catechin and cholesterol, we studied the interaction between typical catechins and cholesterol by the density functional theory. Results show that the adsorption energies between the four catechins and cholesterol are obviously stronger than that of cholesterol themselves, indicating that catechin has an advantage in reducing cholesterol micelle formation. Moreover, it is found that the molecular interactions of the complexes are mainly due to charge transfer of the aromatic rings of the catechins as well as the hydrogen bond interactions. Unlike the intuitive understanding of a complex formed by hydrogen bond interaction, which is positively correlated with the number of hydrogen bonds, the most stable complexes (epicatechin–cholesterol or epigallocatechin–cholesterol) have only one but stronger hydrogen bond, due to charge transfer of the aromatic rings of catechins.

Electronic and structural features of uranium-doped graphene: DFT study

2021 ◽  
pp. 1-7
Author(s):  
Lina Majeed Haider Al-Haideri ◽  
Necla Cakmak
Keyword(s):  
Density Functional ◽  
Energy Levels ◽  
Electronic Conductivity ◽  
Structural Features ◽  
Level Energy ◽  
Size Dependent ◽  
The Density Functional Theory ◽  
Doped Graphene ◽  
Homo And Lumo ◽  
Model Size

Electronic and structural features of uranium-doped models of graphene (UG) were investigated in this work by employing the density functional theory (DFT) approach. Three sizes of models were investigated based on the numbers of surrounding layers around the central U-doped region including UG1, UG2, and UG3. In this regard, stabilized structures were obtained and their electronic molecular orbital features were evaluated, accordingly. The results indicated that the stabilized structures could be obtained, in which their electronic features are indeed size-dependent. The conductivity feature was expected at a higher level for the UG3 model whereas that of the UG1 model was at a lower level. Energy levels of the highest occupied and the lowest unoccupied molecular orbitals (HOMO and LUMO) were indeed the evidence of such achievement for electronic conductivity features. As a consequence, the model size of UG could determine its electronic feature providing it for specified applications.

Electric Field Controlled Separation and Capture of CO2 over S-Doped Graphene: A First-Principles Calculation

2021 ◽  
Vol 43 (6) ◽  
pp. 623-623
Author(s):  
Jingyi Shan Jingyi Shan ◽  
Xiangling Wang Xiangling Wang ◽  
Junkai Wang Junkai Wang ◽  
Shixuan Zhang Shixuan Zhang ◽  
Qianku Hu and Aiguo Zhou Qianku Hu and Aiguo Zhou
Keyword(s):  
Electric Field ◽  
Adsorption Energy ◽  
Greenhouse Effect ◽  
First Principles ◽  
Applied Electric Field ◽  
Density Functional ◽  
Selective Adsorption ◽  
First Principles Calculation ◽  
Combustion Gases ◽  
Doped Graphene

The selective adsorption and capture of CO2 from post-combustion gases carries huge significance for the reduction of greenhouse effect. In this research, the computations of density functional are performed to investigate the CO2 selective adsorption of S-doped graphene in thrall to applied electric field (E-F). Introducing the applied E-F, the adsorption between S-doped graphene and CO2 is strong chemisorption, and CO2 can be effectively captured. Removing the applied E-F, the adsorption restores to physisorption and CO2 is easily desorbed. Therefore, the CO2 seize and clearing can be realized merely by controlling the E-F. Besides, the adsorption energy of N2 (H2O) on S-decorated graphene is positive when introduce the applied E-F. The results demonstrated that S-doped graphene can selectively adsorb CO2 from the post-combustion gases by controlling the E-F.

Density Functional Theory Calculations of Arsenic(III) Structures on Perfect TiO2 Anatase (1 0 1) Surface

2011 ◽  
Vol 233-235 ◽  
pp. 491-494 ◽  
Author(s):  
Lin Yu ◽  
Yue Liu ◽  
Zhi Gang Wei ◽  
Gui Qiang Diao ◽  
Ming Sun ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Adsorption Energy ◽  
Density Functional ◽  
Function Method ◽  
Photocatalytic Oxidation ◽  
Density Functional Theory Calculations ◽  
Functional Theory ◽  
Low Concentrations ◽  
The Density Functional Theory ◽  
The World

There are many areas in the world where the ground water has been contaminated by arsenic. One process to purify the water is to use TiO2 to adsorb the arsenic. As the TiO2 surface can be cleaned and reused, it has a promising potential as a water purifier. In this paper, the plane-wave function method, based on the density functional theory, has been used to calculate the structures of arsenic(III) on a perfect TiO2 anatase (1 0 1) surface. All the arsenic(III) solution species such as H3AsO3, H2AsO3-1, HAsO3-2 and AsO3-3 are put onto the surface with many different possible structures to obtain the adsorption energy. Based on the adsorption energy, the bidentate binuclear (BB) adsorption configurations of arsenic(III) on the surface are more favorable at low concentrations, whereas BB form and monodentate mononuclear (MM) form may coexist at higher concentrations. The models and results fit well with published experimental results. The results and conclusions will be of benefit to further research on arsenite adsorption and its photocatalytic oxidation on a TiO2 surface.

Density Functional Theory Calculations of Arsenic(V) Structures on Perfect TiO2 Anatase (1 0 1) Surface

2011 ◽  
Vol 233-235 ◽  
pp. 495-498 ◽  
Author(s):  
Zhi Gang Wei ◽  
Yan Di Zou ◽  
Hai Xia Zeng ◽  
Xue Chun Zhong ◽  
Zhen Jun Cheng ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Adsorption Energy ◽  
Density Functional ◽  
Function Method ◽  
Photocatalytic Oxidation ◽  
Density Functional Theory Calculations ◽  
Functional Theory ◽  
Low Concentrations ◽  
The Density Functional Theory ◽  
The World

There are many areas in the world where the ground water has been contaminated by arsenic. One process to purify the water is to use TiO2 to adsorb the arsenic. As the TiO2 surface can be cleaned and reused, it has a promising potential as a water purifier. In this paper, the plane-wave function method, based on the density functional theory, has been used to calculate the structures of arsenic(III) on a perfect TiO2 anatase (1 0 1) surface. All the arsenic(III) solution species such as H3AsO3, H2AsO3-1, HAsO3-2 and AsO3-3 are put onto the surface with many different possible structures to obtain the adsorption energy. Based on the adsorption energy, the bidentate binuclear (BB) adsorption configurations of arsenic(III) on the surface are more favorable at low concentrations, whereas BB form and monodentate mononuclear (MM) form may coexist at higher concentrations. The models and results fit well with published experimental results. The results and conclusions will be of benefit to further research on arsenite adsorption and its photocatalytic oxidation on a TiO2 surface.

scholarly journals Computational Study on Substituteds-Triazine Derivatives as Energetic Materials

2012 ◽  
Vol 9 (2) ◽  
pp. 583-592 ◽  
Author(s):  
Vikas D. Ghule ◽  
S. Radhakrishnan ◽  
Pandurang M. Jadhav ◽  
Surya P. Tewari
Keyword(s):  
Thermal Stability ◽  
Energetic Materials ◽  
Density Functional ◽  
Crystal Packing ◽  
Computational Study ◽  
Heats Of Formation ◽  
Dissociation Energies ◽  
The Density Functional Theory ◽  
Triazine Derivatives ◽  
Derivatives Of

s-Triazine is the essential candidate of many energetic compounds due to its high nitrogen content, enthalpy of formation and thermal stability. The present study explores s-triazine derivatives in which different -NO2, -NH2and -N3substituted azoles are attached to the triazine ring via C-N linkage. The density functional theory is used to predict geometries, heats of formation and other energetic properties. Among the designed compounds, -N3derivatives show very high heats of formation. The densities for designed compounds were predicted by using the crystal packing calculations. Introduction of -NO2group improves density as compared to -NH2and -N3, their order of increasing density can be given as NO2>N3>NH2. Analysis of the bond dissociation energies for C-NO2, C-NH2and C-N3bonds indicates that substitutions of the -N3and -NH2group are favorable for enhancing the thermal stability ofs-triazine derivatives. The nitro and azido derivatives of triazine are found to be promising candidates for the synthetic studies.

scholarly journals Influence of catecholic ring torsion on hydroxyflavones

2020 ◽  
Vol 13 (1) ◽  
pp. 49-55
Author(s):  
Martin Michalík ◽  
Monika Biela ◽  
Denisa Cagardová ◽  
Vladimír Lukeš
Keyword(s):  
Gas Phase ◽  
Phenyl Ring ◽  
Density Functional ◽  
Hydroxyl Group ◽  
Torsional Deformation ◽  
Functional Theory ◽  
Electron Transitions ◽  
The Density Functional Theory ◽  
Intramolecular Hydrogen ◽  
Theoretical Results

AbstractSystematic quantum chemical investigation of quercetin and selected eight mono- and bihydroxyflavonols is presented. Structural analysis based on the Density Functional Theory showed that the energetically preferred conformation of flavonols substituted at the C5 and C3 atoms by a hydroxyl group is stabilised via intramolecular hydrogen bonds occurring between the (C4)O···HO(3 or 5) atomic pairs. Depending on the hydroxyl group positions, energetically preferred torsional orientation of the phenyl ring with respect to the planar benzo-γ-pyrone moiety changed from 0 to 180 degrees. Gas-phase electron transitions were investigated using the time-dependent DFT treatment. The dependence of maximal wavelengths on the torsional deformation of the phenyl ring is of a similar shape, i.e. minima observed for the perpendicular orientation and maxima for the planar one. Shape and energies of the Highest Occupied (HOMO) and Lowest Unoccupied (LUMO) Molecular Orbitals were compared. The obtained theoretical results were compared with available experimental data.

scholarly journals Enhancing the Sensing Performance of Zigzag Graphene Nanoribbon to Detect NO, NO2, and NH3 Gases

Sensors ◽  
2020 ◽  
Vol 20 (14) ◽  
pp. 3932 ◽  
Author(s):  
Ehab Salih ◽  
Ahmad I. Ayesh
Keyword(s):  
Charge Transfer ◽  
Gas Sensors ◽  
Adsorption Energy ◽  
Gas Adsorption ◽  
Epoxy Group ◽  
Graphene Nanoribbon ◽  
Hydroxyl Group ◽  
Adsorption Parameters ◽  
Oh Groups ◽  
Sensing Performance

In this article, a zigzag graphene nanoribbon (ZGNR)-based sensor was built utilizing the Atomistic ToolKit Virtual NanoLab (ATK-VNL), and used to detect nitric oxide (NO), nitrogen dioxide (NO2), and ammonia (NH3). The successful adsorption of these gases on the surface of the ZGNR was investigated using adsorption energy (Eads), adsorption distance (D), charge transfer (∆Q), density of states (DOS), and band structure. Among the three gases, the ZGNR showed the highest adsorption energy for NO with −0.273 eV, the smallest adsorption distance with 2.88 Å, and the highest charge transfer with −0.104 e. Moreover, the DOS results reflected a significant increase of the density at the Fermi level due to the improvement of ZGNR conductivity as a result of gas adsorption. The surface of ZGNR was then modified with an epoxy group (-O-) once, then with a hydroxyl group (-OH), and finally with both (-O-) and (-OH) groups in order to improve the adsorption capacity of ZGNR. The adsorption parameters of ZGNR were improved significantly after the modification. The highest adsorption energy was found for the case of ZGNR-O-OH-NO2 with −0.953 eV, while the highest charge transfer was found for the case of ZGNR-OH-NO with −0.146 e. Consequently, ZGNR-OH and ZGNR-O-OH can be considered as promising gas sensors for NO and NO2, respectively.

scholarly journals DFT Analysis of NO Adsorption on the Undoped and Ce-Doped LaCoO3 (011) Surface

Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1379 ◽  
Author(s):  
Xiaochen Li ◽  
Hongwei Gao
Keyword(s):  
Adsorption Energy ◽  
Density Functional ◽  
Adsorption Process ◽  
Dft Method ◽  
Adsorption Site ◽  
No Adsorption ◽  
Functional Theory ◽  
Adsorption Structure ◽  
Preferential Adsorption ◽  
The Density Functional Theory

Using the density functional theory (DFT) method, we investigated the adsorption of NO on the undoped and Ce-doped LaCoO3 (011) surface. According to our calculations, the best adsorption site is not changed after Ce doping. When the NO molecule is adsorbed on the perfect LaO-terminated LaCoO3 (011) surface, the most stable adsorption site is hollow-top, which corresponds to the hollow-NO configuration in our study. After the substitution of La with Ce, the adsorption energy of hollow-NO configuration is increased. For the perfect CoO2-terminated LaCoO3 (011) surface, it is found that Co-NO configuration is the preferential adsorption structure. Its adsorption energy can also be enhanced after Ce doping. When NO molecule is adsorbed on the undoped and Ce-doped LaO-terminated LaCoO3 (011) surface with hollow-NO configuration, it serves as the acceptor and electrons transfer from the surface to it in the adsorption process. On the contrary, for the Co-NO configuration of undoped and Ce-doped CoO2-terminated LaCoO3 (011) surface, NO molecule becomes the donor and loses electrons to the surface.

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