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.

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 Efficiency of the interfacial charge transfer complex between TiO2 nanoparticles and caffeic acid against DNA damage in vitro: A combinatorial analysis

2019 ◽  
Vol 84 (6) ◽  
pp. 539-553
Author(s):  
Vesna Lazic ◽  
Ivana Vukoje ◽  
Bojana Milicevic ◽  
Biljana Spremo-Potparevic ◽  
Lada Zivkovic ◽  
...  
Keyword(s):  
Experimental Data ◽  
Charge Transfer ◽  
Caffeic Acid ◽  
Density Functional ◽  
Visible Spectral Range ◽  
Interfacial Charge Transfer ◽  
The Density Functional Theory ◽  
The Stability ◽  
Interfacial Charge

The genotoxic and antigenotoxic behavior of the interfacial charge transfer (ICT) complex between nano-sized TiO2 particles and caffeic acid (CA) was studied in in vitro experiments. The formation of the ICT complex is indicated by the appearance of absorption in visible-spectral range. The continual variations method indicated bridging coordination between the ligand, caffeic acid, and the surface Ti atoms, while the stability constant of the ICT complex was found to be 1.5?103 mol-1 L. An agreement between the experimental data and the theoretical results, based on the density functional theory, was found. The ICT complex and its components did not display genotoxicity in the broad concentration range 0.4?8.0 mg mL-1 TiO2 at a mole ratio c(TiO2)/c(CA) = 8. On the other hand, post-treatment of damaged DNA by the ICT complex induced antigenotoxic effect at lower concentrations, but at higher concentrations, 5.125?10.250 mg mL-1 ICT, the ICT complex did not show any beneficial effect on H2O2-induced DNA damaged cells. The experimental data were analyzed using the combinatorial method to determine the effect of component interaction on the genotoxic and antigenotoxic behavior of the ICT complex.

scholarly journals Effect of the number of nitrogen dopants on the electronic and magnetic properties of graphitic and pyridinic N-doped graphene – a density-functional study

RSC Advances ◽  
2021 ◽  
Vol 11 (30) ◽  
pp. 18371-18380
Author(s):  
Erik Bhekti Yutomo ◽  
Fatimah Arofiati Noor ◽  
Toto Winata
Keyword(s):  
Magnetic Properties ◽  
Density Functional ◽  
Functional Study ◽  
Density Functional Study ◽  
Electronic And Magnetic Properties ◽  
Doped Graphene ◽  
Dopant Atoms ◽  
Pyridinic N

The number of dopant atoms is a parameter that can effectively tune the electronic and magnetic properties of graphitic and pyridinic N-doped graphene.

scholarly journals Nanotechnology-based approaches for targeting and delivery of drugs via Hexakis (m-PE) macrocycles

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Samaneh Pasban ◽  
Heidar Raissi
Keyword(s):  
Drug Delivery ◽  
Density Functional ◽  
Water Solution ◽  
Decomposition Analysis ◽  
Binding Energies ◽  
Energy Decomposition Analysis ◽  
Partial Density ◽  
High Propensity ◽  
The Stability ◽  
Novel Applications

AbstractHexakis (m-phenylene ethynylene) (m-PE) macrocycles, with aromatic backbones and multiple hydrogen-bonding side chains, had a very high propensity to self-assemble via H-bond and π–π stacking interactions to form nanotubular structures with defined inner pores. Such stacking of rigid macrocycles is leading to novel applications that enable the researchers to explored mass transport in the sub-nanometer scale. Herein, we performed density functional theory (DFT) calculations to examine the drug delivery performance of the hexakis dimer as a novel carrier for doxorubicin (DOX) agent in the chloroform and water solvents. Based on the DFT results, it is found that the adsorption of DOX on the carrier surface is typically physisorption with the adsorption strength values of − 115.14 and − 83.37 kJ/mol in outside and inside complexes, respectively, and so that the essence of the drug remains intact. The negative values of the binding energies for all complexes indicate the stability of the drug molecule inside and outside the carrier's cavities. The energy decomposition analysis (EDA) has also been performed and shown that the dispersion interaction has an essential role in stabilizing the drug-hexakis dimer complexes. To further explore the electronic properties of dox, the partial density of states (PDOS and TDOS) are calculated. The atom in molecules (AIM) and Becke surface (BS) methods are also analyzed to provide an inside view of the nature and strength of the H-bonding interactions in complexes. The obtained results indicate that in all studied complexes, H-bond formation is the driving force in the stabilization of these structures, and also chloroform solvent is more favorable than the water solution. Overall, our findings offer insightful information on the efficient utilization of hexakis dimer as drug delivery systems to deliver anti-cancer drugs.

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.

scholarly journals Ultrafast femtosecond pressure modulation of structure and exciton kinetics in 2D halide perovskites for enhanced light response and stability

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Chunpeng Song ◽  
Huanrui Yang ◽  
Feng Liu ◽  
Gary J. Cheng
Keyword(s):  
Femtosecond Laser ◽  
Density Functional ◽  
Thermal Conditions ◽  
Light Response ◽  
Shock Pressure ◽  
Laser Shock Processing ◽  
The Density Functional Theory ◽  
Pressure Modulation ◽  
The Stability ◽  
Inorganic Framework

AbstractThe carriers’ transportation between layers of two-dimensional (2D) perovskites is inhibited by dielectric confinement. Here, for the first time, we employ a femtosecond laser to introduce ultrafast shock pressure in the range of 0~15.45 GPa to reduce dielectric confinement by modulating the structure and exciton dynamics in a perovskite single crystal (PSCs), e.g. (F-PEA)2PbI4 (4-fluorophenethylammonium, F-PEA). The density functional theory (DFT) simulation and experimental results show that the inorganic framework distortion results in a bandgap reduction. It was found that the exciton-optical phonon coupling and free excitons (FEs) binding energy are minimized at 2.75 GPa shock pressure due to a reduction in dielectric confinement. The stability testing under various harsh light and humid thermal conditions shows that femtosecond laser shocking improves the stability of (F-PEA)2PbI4 PSCs. Femtosecond laser shock processing provides a new approach for regulating the structure and enhancing halide perovskite properties.

Study of the Stability and Chemical Reactivity of a Series of Tetrazole Pyrimidine Hybrids by the Density Functional Theory Method (DFT)

2021 ◽  
Vol 37 (4) ◽  
pp. 805-812
Author(s):  
Ahissandonatien Ehouman ◽  
Adjoumanirodrigue Kouakou ◽  
Fatogoma Diarrassouba ◽  
Hakim Abdel Aziz Ouattara ◽  
Paulin Marius Niamien
Keyword(s):  
Density Functional ◽  
Theoretical Study ◽  
Molecular Descriptors ◽  
Chemical Reactivity ◽  
Density Functional Theory Method ◽  
Functional Theory ◽  
Reactivity Descriptors ◽  
The Density Functional Theory ◽  
The Stability ◽  
Global Reactivity Descriptors

Our theoretical study of stability and reactivity was carried out on six (06) molecules of a series of pyrimidine tetrazole hybrids (PTH) substituted with H, F, Cl, Br, OCH3 and CH3 atoms and groups of atoms using the density function theory (DFT). Analysis of the thermodynamic formation quantities confirmed the formation and existence of the series of molecules studied. Quantum chemical calculations at the B3LYP / 6-311G (d, p) level of theory determined molecular descriptors. Global reactivity descriptors were also determined and analyzed. Thus, the results showed that the compound PTH_1 is the most stable, and PTH_5 is the most reactive and nucleophilic. Similarly, the compound PTH_4 is the most electrophilic. The analysis of the local descriptors and the boundary molecular orbitals allowed us to identify the preferred atoms for electrophilic and nucleophilic attacks.

scholarly journals Structural, elastic, electronic and thermal properties of InAs: A study of functional density

2017 ◽  
Vol 26 (46) ◽  
Author(s):  
Víctor Mendoza-Estrada ◽  
Melissa Romero-Baños ◽  
Viviana Dovale-Farelo ◽  
William López-Pérez ◽  
Álvaro González-García ◽  
...  
Keyword(s):  
Thermal Properties ◽  
Density Functional ◽  
Experimental Studies ◽  
Debye Model ◽  
Band Gap Energy ◽  
Functional Theory ◽  
Zinc Blende ◽  
The Density Functional Theory ◽  
The Stability ◽  
Experimental Values

In this research, first-principles calculations were carried out within the density functional theory (DFT) framework, using LDA and GGA, in order to study the structural, elastic, electronic and thermal properties of InAs in the zinc-blende structure. The results of the structural properties (a, B0, ) agree with the theoretical and experimental results reported by other authors. Additionally, the elastic properties, the elastic constants (C11, C12 and C44), the anisotropy coefficient (A) and the predicted speeds of the sound ( , , and ) are in agreement with the results reported by other authors. In contrast, the shear modulus (G), the Young's modulus (Y) and the Poisson's ratio (v) show some discrepancy with respect to the experimental values, although, the values obtained are reasonable. On the other hand, it is evident the tendency of the LDA and GGA approaches to underestimate the value of the band-gap energy in semiconductors. The thermal properties (V, , θD yCV) of InAs, calculated using the quasi-harmonic Debye model, are slightly sensitive as the temperature increases. According to the stability criteria and the negative value of the enthalpy of formation, InAs is mechanically and thermodynamically stable. Therefore, this work can be used as a future reference for theoretical and experimental studies based on InAs.

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.

Nitrogen-doped carbon supports with terminated hydrogen and their effects on active gold species: a density functional study

2014 ◽  
Vol 16 (46) ◽  
pp. 25498-25507 ◽  
Author(s):  
Junjie Gu ◽  
Qian Du ◽  
You Han ◽  
Zhenghua He ◽  
Wei Li ◽  
...  
Keyword(s):  
Valence State ◽  
Density Functional ◽  
Functional Study ◽  
Carbon Supports ◽  
Acetylene Hydrochlorination ◽  
Density Functional Study ◽  
Nitrogen Doped ◽  
Doped Graphene ◽  
The Stability ◽  
Nitrogen Doped Carbon

The stabilities of gold species on N-doped graphene increase with its valence state. Au2Cl6 interacts preferentially with HCl on N-doped supports, enhancing the stability of Au catalysts for acetylene hydrochlorination.

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