Modeling the Electronic Properties for CNT Interacted with ZnO, CuO and Co3O4

2021 ◽  
Author(s):  
Walaa M. Taha ◽  
Mohamed Morsy ◽  
Nadra A. Nada ◽  
Medhat IBRAHIM
Keyword(s):  
Metal Oxides ◽  
Band Gap ◽  
Electronic Properties ◽  
Band Gap Energy ◽  
Total Dipole Moment ◽  
Adsorbed State ◽  
Complex State ◽  
Hartree Fock ◽  
Mechanism Of Interaction ◽  
Homo Lumo

Abstract Because of the wide applications of carbon nanotubes (CNTs) and magic properties of metal oxides, Hartree-Fock (HF)/STO-3G quantum mechanical calculations were applied to study the electronic properties of CNTs and its interaction with ZnO, CuO and Co3O4. Calculations were conducted to calculate HOMO/LUMO band gap energy ∆E, moleculare electrostatic potential (MESP) and total dipole moment (TDM) for CNTs, CNT-Zn-O, CNT-Cu-O, CNT-Co-O and CNT-O-Zn, CNT-O-Cu, CNT-O-Co following the two mechanism of interaction as adsorbed and complex state. The calculations show that the interaction of CNTs with metal oxides increases its reactivity where MESP indicated to more distribution charges and an increasing in the TDM value after interaction of CNTs with metal oxides. Where, the interaction of CNT-Co-O as adsorbed state has the highest TDM with lowest band gap ∆E which confirms that CNT-Co3O4 can be used in sensing devices.

scholarly journals Effect of hydration on the physical properties of glucose

2019 ◽  
Vol 9 (4) ◽  
pp. 4114-4118 ◽  
Keyword(s):  
Quantum Mechanics ◽  
Dipole Moment ◽  
Band Gap ◽  
Electronic Properties ◽  
Band Gap Energy ◽  
Molecular Electrostatic Potentials ◽  
Total Dipole Moment ◽  
Gap Energy ◽  
Homo Lumo ◽  
Electro Negativity

The effect of hydration on the electronic properties of glucose (Gl) is studied by quantum mechanics by using DFT procedures atB3LYP/6-31g(d,p). Total dipole moment, the highest and the lowest occupied molecular orbital (HOMO/LUMO band gap energy) and molecular electrostatic potentials (ESPs) are calculated at the same level of theory for all model molecules. The results indicated that there is an enhancement in the electronic properties of Gl where TDM of Gl is increased from2.5454Debye to 4.3157Debye while HOMO/LUMO band gap energy is decreased from 13.0994 eV to 3.2749 eV. Also, the calculated ESP results are indicated that the electro-negativity is increased due to hydration which means that the reactivity is increased and hence the electronic properties are improved.

scholarly journals Computational notes on the molecular modeling analyses of flutamide

2020 ◽  
Vol 9 (2) ◽  
pp. 1099-1102
Keyword(s):  
Molecular Modeling ◽  
Active Sites ◽  
Density Functional ◽  
Molecular Electrostatic Potential ◽  
Band Gap Energy ◽  
Total Dipole Moment ◽  
Functional Theory ◽  
Hartree Fock ◽  
Homo Lumo ◽  
Important Drug

Flutamide is one of the recommended and important drug for treating prostate cancer. In spite of this there some scientific reports that recommending against this drug according to some side effects. This is in turn paves the way towards investigating electronic properties of the drug with conventional molecular modeling methods. So that, density functional theory at B3LYP as well as Hartree-Fock HF together with PM3 were utilized to study the drug. Some important parameters are computed in this computational note including total dipole moment, HOMO/LUMO band gap energy and the contour of molecular electrostatic potential in order to map the active sites of the studied drug in terms the charge distributions. Finally, the infrared assignment of the flutamide is introduced based on B3LYP model.

scholarly journals Molecular Modeling Analyses for Electronic Properties of CNT/TiO2 Nanocomposites

2021 ◽  
Author(s):  
H. Elhaes ◽  
M. Morsy ◽  
I. S. Yahia ◽  
M. Ibrahim
Keyword(s):  
Electronic Properties ◽  
Density Functional ◽  
Molecular Electrostatic Potential ◽  
Computational Time ◽  
Bandgap Energy ◽  
Physical Parameters ◽  
Total Dipole Moment ◽  
Complex State ◽  
Functional Theory ◽  
Homo Lumo

Abstract Electronic properties of carbon nanotube (CNT) is enhanced with the help of metal oxides which in turn paves the way toward functionality of CNT for many applications based on their electronic properties. Accordingly, density functional theory at B3LYP/3-21g** is utilized to model the decoration of CNT and TiO 2 . 7 molecules of TiO 2 are interacted with the CNT surface as adsorb state and complex. As a result of this decoration, a change in the Mulliken atomic charges of a carbon atom which is interacted with the metal is recorded, changing both the total dipole moment and HOMO/LUMO bandgap energy. The molecular electrostatic potential is localized toward the left side for the adsorb state then up and down for the complex state, which enhances the probability of forming hydrogen bonding with the surrounding. The change in the physical parameters of the surface promotes the decorated CNT for many applications. For verification, CNT is prepared with homemade CVD then decorated with TiO 2 . XRD, TEM, and TGA confirmed that TiO 2 is located on the surface. Finally, the FTIR spectrum indicated that the studied model is suitable for the investigated system regarding both accuracy and computational time.

Effect of Blending on the Enhancement of Electronic Properties of Biopolymers

2016 ◽  
Vol 13 (10) ◽  
pp. 6800-6802
Author(s):  
Naziha Suliman Alghunaim
Keyword(s):  
Hydrogen Bonding ◽  
Dipole Moment ◽  
Molecular Modeling ◽  
Band Gap ◽  
Electronic Properties ◽  
Band Gap Energy ◽  
The Other ◽  
Total Dipole Moment ◽  
Gap Energy ◽  
Chitosan Blends

Chitosan (Cs), gelatin (Gel) and starch (Str) are blended together to investigate the effect of blending upon the electronic properties of biopolymers. Three blends namely 25%, 50% and 75% of (Cs/Gel) and (Cs/Str) respectively. FTIR were utilized to ensure the occurrence of the proposed blend. The FTIR spectra show the occurrence of hydrogen bonding which indicated that the assigned blend is formed as a result of hydrogen bonding of NH2 and COOH terminals. Electronic properties are indicated with molecular modeling technique at PM6 semiemperical level. Modeling results indicate that, as far as starch and gelatin ratios increased in chitosan blends, the band gap energy is decreased in one hand while the total dipole moment is increased on the other hand.

Geometrical, vibrational and physical properties of polyvinyl chloride nanocomposites: Molecular modeling approach

2019 ◽  
Vol 18 (08) ◽  
pp. 1950037 ◽  
Author(s):  
A. Refaat ◽  
M. A. Ibrahim ◽  
H. Elhaes ◽  
R. Badry ◽  
H. Ezzat ◽  
...  
Keyword(s):  
Infrared Spectrum ◽  
Metal Oxides ◽  
Band Gap ◽  
Polyvinyl Chloride ◽  
Band Gap Energy ◽  
Water Molecules ◽  
Geometrical Parameters ◽  
Molecular Electrostatic Potentials ◽  
Energy Band Gap ◽  
Homo Lumo

B3LYP/6-31G([Formula: see text], [Formula: see text]) quantum mechanical calculations were conducted to study polyvinyl chloride (PVC) and PVC with metal oxides (ZnO and CuO). Accordingly, model molecules for PVC; PVC/[Formula: see text]ZnO; PVC/[Formula: see text]CuO and PVC/[Formula: see text]ZnO/[Formula: see text]CuO, where [Formula: see text] and [Formula: see text], 2 and 3, were proposed. The calculated results of total dipole moment (TDM), HOMO–LUMO energy band gap, and molecular electrostatic potentials (ESPs) indicated that the conductivity of PVC is increased and its surface became more reactive due to interaction with metal oxides. The effect of hydration on PVC was also studied at the same level of theory in order to assess the effect of up to 23 water molecules on PVC. The TDM value of PVC is increased but HOMO/LUMO band gap energy value is decreased because of hydration. Moreover, the results of calculated ESP indicated that the reactivity in the presence of water molecules increased, which could indicate possible degradation of PVC. Additionally, some geometrical parameters were studied. Furthermore, the scaled infrared spectrum (IR) for PVC was also calculated at B3LYP/6-31G ([Formula: see text], [Formula: see text]) and indicated that there are two bands at 2990[Formula: see text]cm[Formula: see text] and 2975[Formula: see text]cm[Formula: see text] in comparison with Fourier transform infrared spectrum (FTIR).

scholarly journals Effect of nano metal oxides on the electronic properties of cellulose, chitosan and sodium alginate

2019 ◽  
Vol 9 (4) ◽  
pp. 4143-4149 ◽  
Keyword(s):  
Metal Oxides ◽  
Sodium Alginate ◽  
Density Functional ◽  
Band Gap Energy ◽  
Organic Polymer ◽  
Model Structure ◽  
Total Dipole Moment ◽  
Functional Theory ◽  
Gap Energy ◽  
Homo Lumo

Study of the effect of some Nano metal oxides MOs as CuO, OCu, ZnO and OZn on some bio-polymers as Cellulose, Chitosan and Sodium Alginate. Thus, model structure of two unit organic polymer Cellulose, Chitosan and Sodium Alginate and they with Nano MOs as CuO, OCu, ZnO and OZn are suggested. Density functional theory (DFT) conducted to study this effect atB3LYP/LANL2DZ. Computed HOMO-LUMO band gap energy(∆E) and Total dipole moment (TDM) indicated that Cellulose and Chitosan affected by Nano MOs that TDM increased and ∆E decrease while Sodium Alginate has a slight change that has no effect on it. Also, calculated electrostatic potential (ESP) indicated that Cellulose and Chitosan affected by Nano MOs specially with CuO while Sodium Alginate has no effect.

scholarly journals Effect of Metal Oxides and Graphene Upon The Electronic Properties of Polyvinyl Alcohol

2021 ◽  
Author(s):  
Maroof A. Hegazy ◽  
Hend A. Ezzat ◽  
Ibrahim S. Yahia ◽  
Heba Y. Zahran ◽  
Hanan Elhaes ◽  
...  
Keyword(s):  
Polyvinyl Alcohol ◽  
Metal Oxides ◽  
Band Gap ◽  
Electronic Properties ◽  
Electrostatic Potential ◽  
Molecular Electrostatic Potential ◽  
Graphene Quantum Dots ◽  
Band Gap Energy ◽  
Electrical Characteristics ◽  
Gap Energy

Abstract Nanomaterials improve the physical and electronic characteristics of polymer matrices, allowing the matrices to be used as low cost, easy to handle sensors. Nano ZnO oxide is forming nanocomposite with PVA modified with graphene. Rather than ZnO other metal oxides are assumed to enhance the electronic properties of PVA modified with graphene (G). Accordingly, Density Function Theory (DFT) was used to analyze model molecules of Polyvinyl Alcohol (PVA) that improved with various metal oxides and graphene quantum dots (GQDs). To show the influence of nanomaterials on PVA matrix behavior, HOMO/LUMO molecular orbitals and Molecular Electrostatic Potential (MESP) mapping were calculated. The B3LYPL/LAN2DZ model was used to calculate the band gap energy ∆E, total dipole moment (TDM), and Molecular Electrostatic Potential (MESP). The obtained results indicated that PVA interacted with MgO, led to a significant improvement in the electrical characteristics. The incorporation of GQDs into PVA/MgO resulted in a novel nanocomposite with good electrical characteristics and a band gap energy ∆E of 0.201 eV, which is intended to be used as a humidity sensor.

scholarly journals On the molecular modeling analyses of sodium carboxymethyl cellulose treated with acetic acid

2019 ◽  
Vol 8 (2) ◽  
pp. 553-557 ◽  
Keyword(s):  
Acetic Acid ◽  
Band Gap ◽  
Carboxymethyl Cellulose ◽  
Density Functional ◽  
Band Gap Energy ◽  
Sodium Carboxymethyl Cellulose ◽  
Functional Theory ◽  
Gap Energy ◽  
Model Molecule ◽  
Homo Lumo

Model molecules for sodium carboxymethyl cellulose (Na-CMC) (monomer), glycerol, acetic acid and Na-CMC-glycerol-acetic acid are optimized with Density Functional Theory (DFT) at B3LYP/3-21G*. For the optimized models, total dipole moment (TDM), the highest occupied and lowest unoccupied molecular orbitals (HOMO/LUMO band gap energy), and molecular electrostatic potentials (ESP) are calculated at the same method to give an explanation for the possibility of using Na-CMC-Glycerol-acetic acid model molecule in electrochemical devices, gas sensors and batteries. As a result of the substitution of Na-CMC with glycerol, TDM increased from 7.7141 Debye to 22.4942 Debye which is approximately equal to three times that of Na-CMC. However, HOMO/LUMO band gap energy decreased from 0.9040 eV to 0.5072 eV. After the addition of acetic acid to Na-CMC-glycerol model, TDM increased to24.7270 Debye and HOMO/LUMO band gap energy decreased to 0.4939 eV. Both TDM and HOMO/LUMO band gap energy values are improved by increasing the acetic acid units, where TDM became 25.3510 Debye and HOMO/LUMO band gap energy decreased to 0.3815 eV. The results of ESP indicated that the addition of glycerol and acetic acid to Na-CMC increased the electronegativity of Na-CMC which in turn enhanced its electronic properties.

scholarly journals Structural, Spectroscopic and Optical Properties of Monohydrated Adenine: A Theoretical Study

2016 ◽  
Vol 64 (2) ◽  
pp. 157-161
Author(s):  
M Alauddin ◽  
MM Islam ◽  
MA Aziz
Keyword(s):  
Optical Properties ◽  
Band Gap ◽  
Theoretical Study ◽  
Minimum Energy ◽  
Band Gap Energy ◽  
Gap Energy ◽  
B3lyp Level ◽  
A Minor ◽  
Homo Lumo ◽  
Hydrogen Bonded

The structural, spectroscopic (IR, NMR and UV-Vis), electronic and optical properties of monohydrated adenine (monohydrated 6-aminopurine, C5H5N5.H2O) are investigated theoretically using DFT/B3LYP level of theory. Three minimum energy structures have been identified for monohydrated of adenine where H2O molecule is doubly hydrogen bonded with adenine.1H NMR analysis shows that the protons which are hydrogen bonded become deshielded and chemical shift moves to the higher frequency region.Five IR active mode of vibrations were found at 3108, 3295, 3665, 3676 and 3719 cm-1 which are assigned as bonded -OH vibration of H2O, Bonded -NH vibration of NH2, Free -NH vibration of adenine (9 N), Free -NH vibration of NH2, Free -OH vibration of H2O, respectively and agree well with the available experimental results. The investigation of electronic properties shows that the HOMO-LUMO band gap energy of monohydrated adenine at B3LYP level is 5.15 eV. The major electronic transition (from HOMO to LUMO (83%) (π→π*)) occurs at 258 nm (4.80 eV) with a minor transition at 237 nm (5.23 eV). Theoretically it is observed that the HOMO-LUMO band gap energy is for monohydrated adenine is lower than that of adenine. Dhaka Univ. J. Sci. 64(2): 157-161, 2016 (July)

Amorphous Semiconductors Studied by First-principles Simulations: Structure and Electronic Properties

2009 ◽  
Vol 1153 ◽  
Author(s):  
Karol Jarolimek ◽  
Robert A. de Groot ◽  
Gilles A. de Wijs ◽  
Miro Zeman
Keyword(s):  
Band Gap ◽  
Electronic Properties ◽  
First Principles ◽  
Density Functional ◽  
Large Cell ◽  
Band Gap Energy ◽  
Amorphous Semiconductors ◽  
Structural Defects ◽  
Defect States ◽  
Wide Range

AbstractAtomistic models of amorphous solids enable us to study properties that are difficult to address with experimental methods. We present a study of two amorphous semiconductors with a great technological importance, namely a- Si:H and a-SiN:H. We use first-principles density functional theory (DFT), i.e. the interatomic forces are derived from basic quantum mechanics, as only that provides accurate interactions between the atoms for a wide range of chemical environments (e.g. brought about by composition changes). This type of precision is necessary for obtaining the correct short range order. Our amorphous samples are prepared by a cooling from liquid approach. As DFT calculations are very demanding, typically only short simulations can be carried out. Therefore most studies suffer from a substantial amount of defects, making them less useful for modeling purposes. We varied the cooling rate during the thermalization process and found it has a considerable impact on the quality of the resulting structure. A rate of 0.02 K/fs proves to be sufficient to prepare realistic samples with low defect concentrations. To our knowledge these are the first calculations that are entirely based on first-principles and at the same time are able to produce defect-free samples. Because of the high computational load also the size of the systems has to remain modest. The samples of a-Si:H and a-SiN:H contain 72 and 110 atoms, respectively. To examine the convergence with cells size, we utilize a large cell of a-Si:H with a total of 243 atoms. As we obtain essentially the same structure as with the smaller sample, we conclude that the use of smaller cells is justified. Although creating structures without any defects is important, on the other hand a small number of defects can give valuable information about the structure and electronic properties of defects in a-Si:H and a-SiN:H. In our samples we observe the presence of both the dangling bond (undercoordinated atom) and the floating bond (over-coordinated atom). We relate structural defects to electronic defect states within the band gap. In a-SiN:H the silicon-silicon bonds induce states at the valence and conduction band edges, thus decreasing the band gap energy. This finding is in agreement with measurements of the optical band gap, where increasing the nitrogen content increases the band gap.

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