scholarly journals Boron-Decorated Pillared Graphene as the Basic Element for Supercapacitors: An Ab Initio Study

2021 ◽  
Vol 11 (8) ◽  
pp. 3496
Author(s):  
Dmitry A. Kolosov ◽  
Olga E. Glukhova

In this work, using the first-principle density functional theory (DFT) method, we study the properties of a new material based on pillared graphene and the icosahedral clusters of boron B12 as a supercapacitor electrode material. The new composite material demonstrates a high specific quantum capacitance, specific charge density, and a negative value of heat of formation, which indicates its efficiency. It is shown that the density of electronic states increases during the addition of clusters, which predictably leads to an increase in the electrode conductivity. We predict that the use of a composite based on pillared graphene and boron will increase the efficiency of existing supercapacitors.

2014 ◽  
Vol 1058 ◽  
pp. 122-126 ◽  
Author(s):  
Hua Zhou ◽  
Zhong Liang Ma ◽  
Jia Hu Guo ◽  
Jian Long Wang

Computations by density functional theory (DFT) method were performed on a series of di-s-tetrazine derivatives with different substituents and linkages. The heat of formation (HOF) was predicted by designed isodesmic reaction. The results illustrated that introductions group –N3or –N=N– could augment the HOF extremely. The crystal structures were obtained by molecular mechanics methods with dreiding force field. Detonation performance was evaluated by using the Kamlet-Jacobs based on the calculated density and HOF. It was found that –ONO2, –NF2, –NH–NH– and –N=N– groups were effective to enhance the detonation performance of these derivatives. Seven compounds were screened as the potential candidates for high energy density materials.


2021 ◽  
Author(s):  
Agnieszka Kącka-Zych ◽  
Radomir Jasinski

Conversion of N-trialkylsilyloxy nitronates into bicyclic isoxazoline derivatives has been explored using Density Functional Theory (DFT) method within the context of the Molecular Electron Density Theory (MEDT) at the B97XD(PCM)/6-311G(d,p)...


Nanomaterials ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 732 ◽  
Author(s):  
Takahiro Shimada ◽  
Koichiro Minaguro ◽  
Tao Xu ◽  
Jie Wang ◽  
Takayuki Kitamura

Beyond a ferroelectric critical thickness of several nanometers existed in conventional ferroelectric perovskite oxides, ferroelectricity in ultimately thin dimensions was recently discovered in SnTe monolayers. This discovery suggests the possibility that SnTe can sustain ferroelectricity during further low-dimensional miniaturization. Here, we investigate a ferroelectric critical size of low-dimensional SnTe nanostructures such as nanoribbons (1D) and nanoflakes (0D) using first-principle density-functional theory calculations. We demonstrate that the smallest (one-unit-cell width) SnTe nanoribbon can sustain ferroelectricity and there is no ferroelectric critical size in the SnTe nanoribbons. On the other hand, the SnTe nanoflakes form a vortex of polarization and lose their toroidal ferroelectricity below the surface area of 4 × 4 unit cells (about 25 Å on one side). We also reveal the atomic and electronic mechanism of the absence or presence of critical size in SnTe low-dimensional nanostructures. Our result provides an insight into intrinsic ferroelectric critical size for low-dimensional chalcogenide layered materials.


Author(s):  
Behnaz Abyaz ◽  
Zabiollah Mahdavifar ◽  
Georg Schreckenbach ◽  
Yang Gao

Evolutionary searches using the USPEX method (Universal Structure Predictor: Evolutionary Xtallography) combined with density functional theory (DFT) calculations were performed to obtain the global minimum structures of beryllium (Ben, n=3-25)...


RSC Advances ◽  
2016 ◽  
Vol 6 (38) ◽  
pp. 31968-31975 ◽  
Author(s):  
Shuai Zhao ◽  
Liguo Gao ◽  
Chunfeng Lan ◽  
Shyam S. Pandey ◽  
Shuzi Hayase ◽  
...  

In this work, we present a detailed first-principles investigation on the stoichiometric and oxygen-deficient structures of double perovskites, Sr2BMoO6 (B = Mg, Co and Ni), using the density functional theory (DFT) method.


2011 ◽  
Vol 2011 ◽  
pp. 1-10 ◽  
Author(s):  
Laura Cecilia Bichara ◽  
Hernán Enrique Lanús ◽  
Evelina Gloria Ferrer ◽  
Mónica Beatriz Gramajo ◽  
Silvia Antonia Brandán

We have carried out a structural and vibrational theoretical study for the citric acid dimer. The Density Functional Theory (DFT) method with the B3LYP/6-31G∗ and B3LYP/6-311++ methods have been used to study its structure and vibrational properties. Then, in order to get a good assignment of the IR and Raman spectra in solid phase of dimer, the best fit possible between the calculated and recorded frequencies was carry out and the force fields were scaled using the Scaled Quantum Mechanic Force Field (SQMFF) methodology. An assignment of the observed spectral features is proposed. A band of medium intensity at 1242  together with a group of weak bands, previously not assigned to the monomer, was in this case assigned to the dimer. Furthermore, the analysis of the Natural Bond Orbitals (NBOs) and the topological properties of electronic charge density by employing Bader's Atoms in Molecules theory (AIM) for the dimer were carried out to study the charge transference interactions of the compound.


2020 ◽  
Author(s):  
Saeedeh Mohammadi ◽  
Mohammad Esmailpour ◽  
Mina Mohammadi

Abstract This paper is a new step in helping the treatment of coronavirus by improving the performance of chloroquine drug. For this purpose, we propose a complex of chloroquine drug with graphene nanoribbon (GNR) scheme. We compute the structural and electrical properties and absorption of chloroquine (C18H26ClN3) and GNR complex using the density functional theory (DFT) method. By creating a drug and GNR complex, the density of states of electrons increases and the energy gap decreases compared to the chloroquine. Also, using absorption calculations and spectrums such as infrared and UV-Vis spectra, we showed that GNR is a suitable structure for creating chloroquine drug complex. Our results show that the dipole moment, global softness and electrophilicity for the drug complex increases compared to the non-complex state. Our calculations can be useful for increasing performance and reducing the side effects of chloroquine, and thus can be effective in treating coronavirus.


2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Ali I. Ismail

Ibrutinib, a Bruton’s tyrosine kinase that plays an essential role in the B-cell development and cancer cells, has been recently approved to treat chronic, lymphocytic, and other types of leukemia. This study focused on investigating ibrutinib by its electronic transitions, vibrational frequencies, and electrospray mass spectra. The experimental peaks for electronic spectrum were found at 248.0 and 281.0 nm, whereas the νC = 0 stretching frequency was found at 1652.4 and 1639.19 cm−1. These experimental properties were compared with the corresponding theoretical calculations in which density functional theory was applied. The optimized structure was obtained with the calculations using a hybrid function (B3LYP) and high-level basis sets [6-311G++(d,p)]. Most of the calculated vibrational frequencies showed a relatively good agreement with the experimental ones. The electronic transitions of ibrutinib calculated using time-dependent DFT method were performed at two different solvation methods: PCM and SMD. The mass spectrum of ibrutinib, its fragments, and its isotopic pattern agreed well with the expected spectra.


2019 ◽  
Vol 41 (6) ◽  
pp. 932-932
Author(s):  
Mengmeng Wu Mengmeng Wu ◽  
Rongkai Pan Rongkai Pan ◽  
Jilei Liang Jilei Liang ◽  
Guohai Zhou Guohai Zhou ◽  
Li Ma and Chunyu Zhang Li Ma and Chunyu Zhang

The γ˝ phase (Mg4GdZn) precipitate in Mg-Gd-Zn alloy was calculated via first-principle density functional theory within the generalized gradient approximation. Through structure optimization of full relaxation, the lattice parameters were theoretically obtained, and the calculated Mg4GdZn is the most energetically stable in view of the formation energy. Independent elastic constants were also calculated, illustrating the calculated Mg4GdZn is mechanically stable. The shear modulus, polycrystalline bulk modulus, Poisson ratio, and Young’s modulus of Mg4GdZn were calculated via the Voigt-Reuss-Hill approximation. Elastic anisotropy and ductility were analyzed in details. Seen from their charge density distribution and electronic density of states, both metallic bond and covalent bond were found in Mg4GdZn.


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