Effect of Al- and Ga-doping on the adsorption of H2 SiCl2 onto the outer surface of boron nitride nanotube: a DFT study

There is a compelling reason to design cost-effective sensors to detect and measure harmful molecules such as dichlorosilane (H2SiCl2) in the air. In this work, density functional theory (DFT) has been used to study the nature of the intermolecular interactions between the gas molecule with a single-walled pristine, Al-doped, and Ga-doped boron nitride nanotubes (BNNT, BNAlNT, and BNGaNT, respectively) to investigate their potential in gas-sensing applications. Full-dimensional geometry optimization and adsorption energies were calculated with four functionals: PBE0, M06-2X, B97XD, and B3LYP-D3 with a 6-311G(d) basis set. We find that the B, Al, or Ga atoms provide the most favorable sites for adsorption of the molecule. The adsorbate is more tightly bound to the surface of the doped rather than of the pristine BNNT nanotubes, demonstrating a larger energy gain due to adsorption. This is due to the fact that interacts with pristine BNNT through weak Van der Waals forces but seemingly has stronger ionic interactions with the doped variants. In general, introducing impurities can improve the selectivity and reactivity of the BNNT toward . Among all of the absorbents, we find that BNGaNT exhibits the highest affinity toward , and therefore holds a higher potential compared to the rest of the nanotubes investigated here for designing materials for dichlorosilane sensors

Vinyl chloride adsorption onto the surface of pristine, Al-, and Ga-doped boron nitride nanotube: A DFT study

The density functional techniques (DFT) were put into practice to study the nature of the intermolecular in�teractions between Vinyl chloride (VCM) gas molecule with single-walled pristine, Al and Ga-doped boron nitride nanotubes (BNNT, BNAlNT, and BNGaNT, respectively). For performing optimization process, various func�tionals including PBE0, M06–2X, ωB97XD, and B3LYP-D3 were applied on both of the isolated and complex structures. All of the functionals were used together with split-valence triple-zeta basis sets with d-type Cartesian�Gaussian polarization functions (6-311G(d)). To consider the electronic structure, total density of state (DOS) analysis were employed. Natural bond orbital (NBO), quantum theory of atoms in molecules (QTAIM), and non�covalent interaction (NCI) analyses were also taken on board to discover the nature of intermolecular in�teractions between gas and nanotubes. The results of electronic structure calculations as well as population analyses has been carefully tabulated and partially depicted. The HOMO-LUMO energy gap (HLG) were dramatically changed when the dopant atom added to the BNNT. It means the impurity can improve the sensivity and reactivity of the pristine nanotube; therefore, by absorbing the VCM onto the surface of the titled nanotubes, a salient signal can produce in a typical electronic circuit. Among all of the absorbents, BNGaNT shows the most favorable material to design a nanosensor for the studied gas molecule

The adsorption of bromochlorodifluoromethane on pristine and Ge-doped silicon carbide nanotube: a PBC-DFT, NBO, and QTAIM study

In the present investigation, the feasibility of detecting the bromochlorodifluoromethane (BCF) gas molecule onto the outer surface of pristine single-wall silicon carbide nanotube (SiCNT), as well as its germanium-doped structures (SiCGeNT), was carefully evaluated. For achieving this goal, a density functional theory level of study using the Perdew, Burke, and Ernzerhof exchange-correlation (PBEPBE) functional together with a 6-311G(d) basis set has been used. Subsequently, the B3LYP, CAM-B3LYP, ωB97XD, and M06-2X functionals with a 6-311G(d) basis set were also employed to consider the single-point energies. Natural bond orbital (NBO) and quantum theory of atoms in molecules (QTAIM) were implemented by using the PBEPBE/6-311G(d) method, and the results were compatible with the electronic properties. In this regard, the total density of states (TDOSs), the Wiberg bond index (WBI), natural charge, natural electron configuration, donor-acceptor natural bond orbital interactions, and the second-order perturbation energies are performed to explore the nature of the intermolecular interactions. All of the energy calculations and population analyses denote that by adsorping of the gas molecule onto the surface of the considered nanostructures, the intermolecular interactions are of the type of strong physical adsorption. The doped nanotubes have a very high adsorption energy compared with pristine nanotube. Generally, it was revealed that the sensitivity of the adsorption will be increased when the gas molecule interacts with decorated nanotubes and decrease the HOMO-LUMO band gap; therefore, the change of electronic properties can be used to design suitable nanosensors to detect BCF gas

Adsorption of alkali and alkaline earth ions on nanocages using density functional theory

The adsorption of alkali and alkaline earth ions onto the exterior surface of inorganic nanocages X12Y12 (X = B, Al, Ga and Y = N, P, As) was investigated by using the density functional theory (DFT). All of the configurations, including the pristine ions or nanocages, as well as the ion adsorbed nanocage systems, were optimized using B3LYP-D3 functional and DEF2-TZVP basis sets. Comparative single point energy calculations were performed using different functionals viz. B3LYP-D3, M06-2X, ωB97XD and CAM-B3LYP, together with DEF2-TZVP and DEF2-QZVP basis sets. The results of natural bond orbital (NBO), quantum theory of atoms in molecules (QTAIM), and non-covalent interaction (NCI) analyses were compatible with the results of electronic properties. Total density of states (TDOSs), the natural charge, Wiberg bond index (WBI), natural electron configuration, donor–acceptor NBO interactions and second-order perturbation energies are obtained. Strong interaction between the ions and the nanocages is observed and the tendency of the ions to adsorb onto the surfaces of the mentioned X12Y12 nanocages is in the order Be++ > Mg++ > Ca++ > Li+ > Na+ > K+. These nanocages may be potential sensors for these alkali and alkaline earth ions

Relationship between radon concentration and physicochemical parameters in groundwater of Erbil city, Iraq

This study portrays the relationship between Radon activity concentration and physicochemical parameters in groundwater in Erbil city, Iraq. Primary data of groundwater samples were collected from five different zones in Erbil, during February 2019. Water samples were collected for both Radon measurement and physicochemical analysis. Water samples were taken from 24 different wells as a reference, then directly measured their radioactivity at the laboratory of Erbil Environment Office. Dissolved Radon 222Rn in a sampled groundwater has been measured using an electronic Radon detector RAD 7. Determination of various parameters such as pH, total dissolved solids, total hardness, Sulfate, and Magnesium in groundwater has also been measured. Moreover, regression analysis illustrated that there is no significant relationship observed between pH, TDS, and hardness, Sulfate, and Magnesium with Radon activity concentration because these are no significant at the 95% confidence level. Otherwise, the correlation of determinate (R2) values show the relationship between Sulfate and Magnesium with Radon concentration because these are significant at the 95% confidence level. All measurements were done in almost identical environmental conditions to avoid the minor differences in meteorological parameters

Nuclear Gamma-soft Character in ¹²⁸Ba

We report the properties of gamma soft O(6) of 128Ba isotones with neutron N = 72 using Interacting Vector Boson Model (IVBM), interacting Boson Model (IBM-1), Bohr-Mottelson Model (BM), and Doma-El-Gendy (D-G) relation. The first energy level ( ) and ratio have been investigated which show that 128Ba has gamma-soft character. The curves Eγ/Vs.J of E-GOS of even 128Ba nucleus were compared with the standard curves of vibrational, gamma soft and rotational limits. The staggering factors were studied of available measured data of 128Ba nucleus. The yrast levels of this isotope are calculated by the model of VBMI, IBM-1, BM and D-G and they were compared by measured data. The negative parity band of 128Ba was calculated by IVBM and BM model and compared with experimental values

Theoretical investigation of X12O12 (X = Be, Mg, and Ca) in sensing CH2N2: A DFT study

The feasibility of detecting diazomethane (CH2N2) in the gas phase by adsorption onto the exterior surface of inorganic-based X12O12 (where X can be Be, Mg, or Ca) nanocages is investigated here using DFT. All the structures, including those of the pristine CH2N2 and of the nanocages, as well as of the CH2N2/nanocage systems, have been optimized using the B3LYP-D3, M06-2X, ωB97XD, and CAM-B3LYP functionals, in conjunction with 6-311G(d) basis set. NBO, NCI, and QTAIM analyses results are in good agreement with each other. Furthermore, the Density Of States (DOSs), the natural charges, the Wiberg Bond Indices (WBI), and natural electron configurations were considered to investigate the nature of intermolecular interactions. The energy calculations indicate a strong size-dependent adsorption, with the nanocages comprised of large atoms being able to attract CH2N2 more strongly, and hence bind with it more effectively. The adsorption incurs also significant changes to HOMO and LUMO energies

The adsorption of chlorofluoromethane on pristine, and Al- and Ga-doped boron nitride nanosheets: a DFT, NBO, and QTAIM study

In the present investigation, the feasibility of detecting the chlorofluoromethane (CFM) gas molecule onto the outer surface of pristine single layer boron nitride nanosheet (BNNS), as well as its aluminum (Al)– and gallium (Ga)–doped structures, was carefully evaluated. For achieving this goal, a density functional theory level of study using the Perdew, Burke, and Ernzerhof exchange–correlation (PBEPBE) functional together with a 6-311G(d) basis set has been used. Subsequently, the B3LYP, CAM-B3LYP, wB97XD, and M062X functionals with a 6-311G(d) basis set were also employed to consider the single-point energies. Natural bond orbital (NBO) and quantum theory of atoms in molecules (QTAIM) were implemented by using the B3LYP-D3/6-311G(d) method, and the results were compatible with the electronic properties. In this regard, the total density of states (TDOSs), the Wiberg bond index (WBI), natural charge, natural electron configuration, donor–acceptor natural bond orbital interactions, and the second-order perturbation energies are performed to explore the nature of the intermolecular interactions. All of the energy calculations and population analyses denote that by adsorbing of the gas molecule onto the surface of the considered nanostructures, the intermolecular interactions are of the type of strong chemical adsorption. Among the doped nanosheets, Ga-doped nanosheet has very high adsorption energy compared with other elements (i.e., Ga-doped > Al-doped > pristine). Generally, it was revealed that the sensitivity of the adsorption will be increased when the gas molecule interacts with decorated nanosheets and decrease the HOMO-LUMO band gap; therefore, the change of electronic properties can be used to design suitable nanosensors to detect CFM gas

Theoretical study of the adsorption of amantadine on pristine, Al-, Ga-, P-, and As-doped boron nitride nanosheets: a PBC-DFT, NBO, and QTAIM study

Nowadays, nanostructures such as nanotubes and nanosheets are widely used in industry, especially the medical industry, for drug delivery, prevention and treatment. In the present investigation, the feasibility of detecting the amantadine gas molecule onto the outer surface of pristine single layer boron nitride nanosheet, as well as its aluminum (Al)-, gallium (Ga)-, phosphorus (P)-, and arsenic (As)-doped structures, was carefully evaluated. For achieving this goal, a periodic boundary condition density functional theory level of study using the HSEH1PBE functional together with a 6-311G (d) basis set has been used. Subsequently, the B3LYP-D3, wB97XD, and M062X functionals with a 6-311G (d) basis set were also employed to consider the single point energies. Subsequently, the B3LYP-D3 (BJ)/6-31G (d) method was also used to consider the contribution of scattering interactions to energy analyzes, natural bond orbital and quantum theory of atoms in molecules and the results were compatible with the electronic properties. In this regard, the total density of states, the Wiberg bond index, natural charge, natural electron configuration, donor–acceptor natural bond orbital interactions, and the second-order perturbation energies are performed to explore the nature of the intermolecular interactions. All of the calculations and analyses denote that by adsorbing of the amantadine molecule onto the surface of pristine boron nitride nanosheet, the adsorption is of the type of physical adsorption and van der Waals interactions. Among the doped nanotubes, gallium-doped nanotube has a very high adsorption energy compared to other elements, and is expected to be chemically adsorbed in this case and appears to be a suitable drug delivery option