scholarly journals BCl3 Adsorption on Pristine, S-Doped, and Cr-Doped Graphynes: A DFT Study

2021 ◽  
Author(s):  
Maryam Derakhshandeh
Keyword(s):  
Electrical Conductivity ◽  
Density Functional Theory ◽  
Work Function ◽  
Density Functional ◽  
Adsorption Process ◽  
Function Type ◽  
Functional Theory ◽  
Density Functional Theory Computations ◽  
Homo Lumo ◽  
Electronic Signal

Abstract The adsorption of boron trichloride (BCl3) was explored onto pristine, S-doped, and Cr-doped graphyne through density functional theory computations. The interaction of BCl3 with pristine graphyne was weak and, thus, this sheet cannot be used as a sensor. Although S-doping strengthens the interaction, the S-doped sheet cannot still be used as a sensor. However, the reactivity and sensitivity of the sheet are significantly increased toward BCl3 by replacing the C atom of graphyne with the transition metal Cr. The HOMO-LUMO gap of Cr-doped graphyne reduces from 2.18 to 1.38 eV following the adsorption of BCl3, which significantly increases the electrical conductivity. Thus, the great change in the conductivity can be converted into an electronic signal, indicating that Cr-doped graphyne may be a promising sensor for BCl3. Also, its work function is considerably decreased by the adsorption process, indicating that it can also work as a work function-type sensor for BCl3 detection.

scholarly journals PH3 and AsH3 Adsorption Through Pristine and Stone-Wales Defected Zinc Oxide Nanosheets: A Density Functional Theory Study

2021 ◽  
Author(s):  
Mohammad Reza Poor Heravi
Keyword(s):  
Electrical Conductivity ◽  
Density Functional Theory ◽  
Zinc Oxide ◽  
Electronic Properties ◽  
Density Functional ◽  
Density Functional Theory Study ◽  
Functional Theory ◽  
Density Functional Theory Computations ◽  
Homo Lumo ◽  
Zinc Oxide Nanosheets

Abstract The adsorption of the XH3 (X = As or P) molecules were explored onto a pure and Stone-wales defected ZnONS (SW ZnONS) through density functional theory computations. As XH3 approaches the pure ZnONS their adsorption releases -3.7 to -7.6 kcal/mol, indicating a physisorption. Also, the electronic properties of the nanosheet do not change significantly. But when AsH3 approaches SW ZnONS, its adsorption releases -23.3 kcal/mol, and electronic analysis showed that the SW ZnONS HOMO/LUMO gap reduces about ~ -27.1% and the electrical conductivity increases significantly. Therefore, the SW ZnONS can generate electrical signals when the AsH3 molecule approaches, being a hopeful sensor. τ value which calculated for the desorption of AsH3 from the surface of the SW ZnONS is 9.5 s. This indicates that the SW ZnONS has the advantage of having a short τ as a sensor for AsH3 detection.

scholarly journals Pt doped boron carbide monolayer nanosheet as a work function-type sensor for ibuprofen drug; quantum chemical study

2021 ◽  
Author(s):  
liang Wu
Keyword(s):  
Work Function ◽  
Electron Emission ◽  
Quantum Chemical ◽  
Recovery Time ◽  
Density Functional ◽  
Quantum Chemical Study ◽  
Chemical Study ◽  
Function Type ◽  
Functional Theory ◽  
Homo Lumo

Abstract Through density functional theory (DFT), the sensitivity of the Pt-doped and the pristine BC3 nanosheets to ibuprofen (IBP) was scrutinized. The IBP drug does not impact the electronic properties evaluated for the pristine BC3. However, its sensitivity and reactivity are increased to the IBP drug to a great extent after doping it by Pt. Unlike the pristine BC3, the adsorption of the IBP drug decreases the HOMO-LUMO gap associated with the Pt-doped BC3 sheet from 1.29 to 1.04 eV, which improves the electrical conductivity. In addition, the adsorption of the IBP drug will mainly impact the work function of the Pt-doped BC3 sheet, which in turn modifies the electron emission current from its sheet. This verifies that the Pt-doped BC3 sheet can be utilized as a work-function-type sensor to detect the IBP drug. For desorption of the IBP drug, the recovery time of the Pt-BC3 nanosheet is short, i.e., 5.65 ms, which is another advantage of this sheet.

Mechanistic insights into α-branched amines formation with pivalic acid assisted C−H bond activation catalysed by Cp*Rh complexes

2021 ◽  
Author(s):  
Rongrong Li ◽  
Xinzheng Yang
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Bond Activation ◽  
Pivalic Acid ◽  
Activation Mechanism ◽  
Functional Theory ◽  
Density Functional Theory Computations ◽  
Reaction Energies

Density functional theory computations revealed a pivalic acid assisted C−H bond activation mechanism for rhodium catalyzed formation of α-branched amines with C−C and C−N bond couplings. The reaction energies of...

STRUCTURES, ABSORPTION SPECTRA, AND ELECTRONIC PROPERTIES OF POLYFLUORENE AND ITS DERIVATIVES: A THEORETICAL STUDY

2006 ◽  
Vol 05 (03) ◽  
pp. 595-608 ◽  
Author(s):  
KRIENGSAK SRIWICHITKAMOL ◽  
SONGWUT SURAMITR ◽  
POTJAMAN POOLMEE ◽  
SUPA HANNONGBUA
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Energy Gap ◽  
Level Energy ◽  
Excitation Energies ◽  
Lumo Energy ◽  
Functional Theory ◽  
Local Energy Minimum ◽  
Pi Systems ◽  
Homo Lumo

The structural and energetic properties of polyfluorene and its derivatives were investigated, using quantum chemical calculations. Conformational analysis of bifluorene was performed by using ab initio (HF/6-31G* and MP2/6-31G*) and density functional theory (B3LYP/6-31G*) calculations. The results showed that the local energy minimum of bifluorene lies between the coplanar and perpendicular conformation, and the B3LYP/6-31G* calculations led to the overestimation of the stability of the planar pi systems. The HOMO-LUMO energy differences of fluorene oligomers and its derivatives — 9,9-dihexylfluorene (DHPF), 9,9-dioctylfluorene (PFO), and bis(2-ethylhexyl)fluorene (BEHPF) — were calculated at the B3LYP/6-31G* level. Energy gaps and effective conjugation lengths of the corresponding polymers were obtained by extrapolating HOMO-LUMO energy differences and the lowest excitation energies to infinite chain length. The lowest excitation energies and the maximum absorption wavelength of polyfluorene were also performed, employing the time-dependent density functional theory (TDDFT) and ZINDO methods. The extrapolations, based on TDDFT and ZINDO calculations, agree well with experimental results. These theoretical methods can be useful for the design of new polymeric structures with a reducing energy gap.

CH2O Adsorption on M (M = Li, Mg and Al) Atom Deposited ZnO Nano-Cage: DFT Study

2018 ◽  
Vol 786 ◽  
pp. 384-392 ◽  
Author(s):  
Hussein Y. Ammar
Keyword(s):  
Density Functional Theory ◽  
Bond Length ◽  
Density Functional ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Structural And Electronic Properties ◽  
Formaldehyde Molecule ◽  
Electronic Configurations ◽  
Adsorption Energies ◽  
Homo Lumo

The structural and electronic properties of Li, Mg and Al deposited ZnO nanocages and their effects on the adsorption of formaldehyde molecule have been investigated using the density functional theory (DFT) computations. To understand the behavior of the adsorbed CH2O molecule on the ZnO nanocage, results of DFT calculations of the M-deposited nanocages (M=Li, Mg and Al), as well as complex systems consisting of the adsorbed CH2O molecule on M-deposited ZnO nanocage were reported. The results presented include adsorption energies, bond lengths, electronic configurations, density of states and molecular orbitals. It was found that, the most energetically stable adsorption configurations of CH2O molecule on the bare ZnO leads to 12% dilation in C=O bond length of CH2O and 14% decrease in HOMO-LUMO gap of ZnO cluster. The most energetically stable adsorption configurations of CH2O molecule on Li, Mg and Al-deposited ZnO lead to 4%, 4% and 11% dilation in C=O bond length of CH2O and-0.66, -45 and , +66% change in HOMO-LUMO gap of ZnO nanocages, respectively. The interaction between CH2O with bare ZnO and M-deposited ZnO nanocages is attributed to charge transfer mechanism. These results may be meaningful for CH2O degradation and detection.

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