Doped Boron Nitride Nanotubes Research Articles

Ibuprofen adsorption and detection of pristine, Fe–, Ni–, and Pt–doped boron nitride nanotubes: A DFT investigation

The main challenge has been focused on ibuprofen drug detection and adsorption of boron nitride nanotube (BNNT) doping with transition metal (TM = Fe, Ni, and Pt) atoms using the density functional theory calculation in gas and water phases. The geometrical structures, adsorption energies, solvation energies, and electronic properties were examined. The optimized geometries show that the ibuprofen molecule oriented itself at different bond distances and angles with respect to BNNT surface. The calculated results display exothermic adsorption processes for all ibuprofen/BNNT and ibuprofen/TM–doped BNNT complexes. Ibuprofen molecule can absorb on the Fe–, Ni–, and Pt–doped BNNTs via a stronger interaction than those of pristine BNNT in both gas and water phases in which the Fe doping on N site of BNNT shows the strongest interaction with ibuprofen molecule. The H (head) site of ibuprofen molecule to BNNT surface shows stronger interaction than M (middle) and T (tail) sites. The short of adsorption distance and the large of charge transfer correspond to the high adsorption strength of TM–doped BNNTs toward ibuprofen molecule. Charge analysis confirms the partial charge transfer occurring from the ibuprofen molecule to the BNNTs. The solvation energies in water solution reveal that the ibuprofen molecule adsorbed on TM–doped BNNTs is more soluble than pristine BNNT. The work functions of BNNTs are reduced by ibuprofen adsorption. A short recovery times and suitable desorption temperatures are observed for the ibuprofen desorption on pristine BNNT and TM–doped BNNT surfaces. After ibuprofen adsorption, the energy levels and energy gaps of Fe–, Ni–, and Pt–doped BNNTs are changed in which Ni doping on B atom of BNNT displays the largest change. The quantum molecular characteristics of BNNT will be changed after ibuprofen adsorption. The orbital distributions are occurred around the ibuprofen molecule and doping site. The alteration in the density of states for TM–doped BNNT is considerably more pronounced compared to the pristine BNNT. Drawing from the achieved outcomes, it can be inferred that when employed for the delivery of ibuprofen in biological media, Fe–, Ni–, and Pt–doped BNNTs exhibits the greater suitability for the adsorption and detection of the ibuprofen molecule compared to pristine BNNT.

Density Functional Theory Investigation on the Structural and Electronic Properties of Pristine, Vacancy, and Group IV Doped Zigzag Boron Nitride Nanotubes

In this work, density functional theory (DFT) calculations were conducted to study the structural and electronic properties of pure, vacancy, and group IV [i.e. carbon (C), silicon (Si), and germanium (Ge) atoms] doped boron nitride nanotubes (BNNTs). The DFT computational results obtained agree well with the literature results. The calculated B−N bond distances obtained in this study are about 1.44 Å – 1.47 Å. Among seven BNNTs, the optimized B35GeN36H12 holds the lowest local energy minimum value in this study Moreover, the structure of B35CN36H12 possesses the smallest HOMO−LUMO energy (2.17 eV) among nine BNNT models considered. The boron (B) atoms hold the positive charges, and the negative charges fall on the nitrogen (N) atoms in this work. Similar results are reported to the molecular electrostatic potentials (MEPs) of studied BNNTs. The distributions of positive and negative electrostatic potentials fall on the regions of N− and B−tips of BNNT frameworks, respectively in this report. The DFT calculations reported that the spin densities were mainly concentrated in the regions around group IV elements, such as C, Si, and Ge atoms. Therefore, we believe that these computed results will provide useful information on the adsorption of hydrogen molecules on the BNNT frameworks in the future.

Insights on the enhanced hydrogen sulfide adsorption on X (X = Cr, Ni, Al, C, Si, O, S) doped boron nitride nanotubes

This study investigates the enhanced hydrogen sulfide (H2S) gas adsorption on X (X = Cr, Ni, Al, C, Si, O, and S) doped boron nitride nanotubes (BNNT) through first-principle density functional theory calculations. The study also examined the electrostatic potential maps, HOMO-LUMO distributions, density of states plots, atomic charges, and reactivity descriptors of doped BNNT clusters before and after adsorption. The H2S orientation was different for each optimized doped BNNT-H2S cluster. The theoretical infrared spectra indicated a red shift in the SH symmetric stretching frequency of H2S gas molecule upon adsorption on pristine and doped BNNT. The examination of the atomic charges showed that during the interaction, the charge was transferred from the doped BNNT to the H2S gas molecule. The analysis revealed that Al/BNNT and S/BNNT exhibited better interactions and, therefore, better adsorption ability towards H2S gas than pristine and other doped BNNT. However, considering the recovery time aspect, C/BNNT, O/BNNT, and Si/BNNT were better adsorbent for H2S.

A DFT approach to the adsorption of the Levodopa anti-neurodegenerative drug on pristine and Al-doped boron nitride nanotubes as a drug delivery vehicle

The adsorption behavior of the anti-neurodegenerative drug Levodopa (LD) on pristine and aluminum-doped (Al-doped) boron nitride nanotubes (BNNTs) has been investigated in the current study using the density functional theory (DFT) approach at the B3LYP/6-31G** level of theory. The aim was to improve and expand boron nitride nanotubes drug carriers used in biomedical systems, i.e., drug delivery systems. The binding qualities of pure and doped BNNT complexes as adsorbents with LD were explored using the natural bond orbitals (NBO) analysis, density of state (DOS), electrical and structural characteristics, and atoms in molecules (AIM) properties. Due to doping heteroatoms in the adsorbent's molecular structure, the obtained data reveal a gradual shift in LD adsorption, with a significant rise in negative adsorption energy values. The electronic perturbation caused by doped atoms, particularly Al, improves boron nitride nanotube sensitivity to adsorbed Levodopa, and the electronic properties of the nanotubes are altered following Levodopa adsorption in the complex. As the frontier molecular orbital distributions were transferred from LD to BNNTs in the complex of BNNT–LD, it was also shown that LD drugs could be loaded on pristine and Al-doped BNNTs while remaining safe from interactions with other substances. Furthermore, AIM analysis based investigations revealed that O–Al interaction in LD adsorbed on Al-doped boron nitride nanotube and O–N interaction in the BNNT–LD complex are partially covalent. Finally, the findings showed that pristine and Al-doped BNNT could be used in drug delivery processes by controlling the loaded LD contribution to future interactions.

Engineering the thermodynamic properties of carbon doped boron nitride nanotubes by impurity concentration and electric field

The effects of the impurity concentration and electric field strength on the electronic and thermal properties of carbon doped boron nitride nanotubes are investigated by the tight binding model, Kubo-Greenwood formula and Green function approach. The position, intensity and number of the density of sate peaks are affected by electric field strength F and dopant concentration which leads to band gap reduction in the doped boron nitride nanotubes compared to the pure boron nitride nanotubes. The thermal functions of the doped boron nitride nanotubes are zero first in very low temperature due to existing the large band gap and become zero by increasing the temperature until reach their maximum values at TM and finally decrease significantly in higher temperature above the TM. The increasing (decreasing) pattern in low (high) temperature region occurs due to the band gap modifications (scattering and collision between charge carriers) and for all selected structures, they are related to the electric field strength and doping concentration. The Lorenz number of the doped boron nitride nanotubes with and without the electric field has a peak with LMax intensity at TM which in the presence of the external electric field, it moves to lower temperature with decreasing intensity. By increasing the nanotube radius, the thermal properties of the doped boron nitride nanotubes increase in terms of the temperature and this behavior becomes valid in the presence of the electric field.

Interaction of Fluorouracil drug with boron nitride nanotube, Al doped boron nitride nanotube and BC2N nanotube

The boron nitride nanotube (BNNT), Al-doped boron nitride (BAlNNT), and BC2N nanotube nanotubes (BC2NNT) have been used to use their outer surface as a suitable substrate for the adsorption of the Fluorouracil (5-FU) drug molecule. The computational framework used in the study of intermolecular interactions of species participating in the adsorption process was density functional theory (DFT). Various functionals, including PBE0, M06-2X, ωB97XD, and B3LYP-D3 have been employed to study the effects of electronic properties well. Also, the successful basis set 6-311G(d) has been used in all calculations. Different wave function analyses have been used to determine the type of intermolecular interactions, including natural bond orbital (NBO), non-covalent interactions (NCI), quantum theory of atoms in molecules (QTAIM) using B3LYP-D3/6-311G(d) model chemistry. All methods reveal the consistency and physical adsorption of the drug molecule onto the nanostructures. The strength and sensitivity of adsorption between the mentioned nanotubes are BAlNNT > BC2NNT > BNNT. The HOMO–LUMO energy gaps are found to be 6.545, 8.127, and 7.027 eV for BNNT, BNAlNT, and BC2NNT respectively, and depicted through the density of states (DOS) diagrams. Higher 5-FU drug adsorption energy for Al-doped BNNT indicates that the Al-doped BNNT can be used to design a 5-FU drug nanocarrier.

A novel bionanosensor for dopamine detection based on titanium doped single walled boron nitride nanotube: Density functional theory

The development of new generation of nanobiosensors and other nanomedicine devices are urgently needed. In this study, we used computer simulations to study the interaction of titanium doped boron nitride nanotubes with dopamine under vacuum and solvent conditions. Our results revealed that the interaction between dopamine and boron nitride nanotube can be tuned via Ti-atom doping, which in turn facilitates the development of new generation of nanomedicine devices. Despite the medium conditions, it was found that the Ti-doped configurations are more stable and more conductive compared to the un-doped configurations. The stability of the investigated configurations under solvent conditions provides an opportunity to investigate real cases in human body. Moreover, it was found that the energy gap of the investigated structures is crucially dependent on the dopamine orientation with respect to the doped nanotube. Our results are thus expected to be very useful for the development of the next generation of nanobiosensors.

Ab Initio Study of TEPA Adsorption on Pristine, Al and Si Doped Carbon and Boron Nitride Nanotubes

The present first principles study entails the adsorption behavior of N, Nʹ, Nʺ-triethylenephosphoramide (TEPA) drug over the pristine, Si- and Al-doped (5, 5) armchair single-wall carbon and boron-nitride nanotubes (SWCNTs and SWBNNTs). Density functional theory (DFT) calculations were done via the B3LYP and M06-2X methods with the standard 6-31G** basis set. The results show that the adsorption of TEPA drug molecule occurred physically on pristine CNT and BNNT and chemically on Al- and Si-doped CNTs and BNNTs. Although Si- and Al-doped CNTs and Al-doped BNNT provide stronger adsorption, the change in the energy gap of the Si-doped BNNT was more pronounced. The lipophilicity calculations indicated that the pure, Si- and Al-doped BNNTs are better candidates for increasing the efficiency of TEPA drug. It has been predicted that the Si-doped BNNT may be a promising drug delivery agent.

Adsorption of carbon dioxide and ammonia in transition metal-doped boron nitride nanotubes.

Density functional theory calculations were carried out to analyze the performance of single-walled boron nitride nanotubes (BNNT) doped with Ni, Pd, and Pt as a sensor of CO2 and NH3. Binding energies, equilibrium distances, charge transference, and molecular orbitals, as well as the density of states, are used to study the adsorption mechanism of the gas species on the surface of the nanotube. Our results suggest a considerable rise in the adsorption potential of BNNTs when the doping scheme is employed, as compared with adsorption in pristine nanotubes. Ni-doped nanotubes are observed to be the best candidates for adsorption of both carbon dioxide and ammonia. Graphical Abstract Molecular orbitals distribution for CO2 adsorption on a Boron Nitride Nanotube.

Nitrogen monoxide storage and sensing applications of transition metal–doped boron nitride nanotubes: a DFT investigation

The structural properties, electronic properties, and adsorption abilities for nitrogen monoxide (NO) molecule adsorption on pristine and transition metal (TM = V, Cr, Mn, Nb, Mo, Tc, Ta, W, and Re) doping on B or N site of armchair (5,5) single-walled boron nitride nanotube (BNNT) were investigated using the density functional theory method. The binding energies of TM-doped BNNTs reveal that the Mo atom doping exhibits the strongest binding ability with BNNT. In addition, the NO molecule weakly interacts with the pristine BNNT, whereas it has a strong adsorption ability on TM-doped BNNTs. The increase in the adsorption ability of NO molecule onto the TM-doped BNNTs is due to the geometrical deformation on TM doping site and the charge transfer between TM-doped BNNTs and NO molecule. Moreover, a significant decrease in energy gap of the BNNT after TM doping is expected to be an available strategy for improving its electrical conductivity. These observations suggest that NO adsorption and sensing ability of BNNT could be greatly improved by introducing appropriate TM dopant. Therefore, TM-doped BNNTs may be a useful guidance to be storage and sensing materials for the detection of NO molecule.

Electronic Structure of Doped Boron Nitride Nanotubes as Potential Catalysts of Photochemical Water Splitting

Semiconductors with band gap widths of 1.5–2.8 eV are used as catalysts for hydrogen production by photochemical water splitting. The electronic states of BN nanotubes doped with Group III–V nontransition elements have been studied by quantum-chemical methods. It has been found that nanotubes with a small excess of boron or with carbon atoms substituted for some boron atoms can be used as candidates for creation of such catalysts since they have optical absorption in this spectral range.

The interaction of propargylamine-based sulfonamide with pristine, Al and Si doped boron nitride nanotubes: A theoretical study

Interactions of a bioactive propargylamine-based sulfonamide with the pristine, Al, and Si doped boron nitride nanotubes (BNNT) were studied using density functional theory calculations. The relative reactivity of the studied nanotubes toward the sulfonamide-based compound was as: Al-doped≫Si-doped>pristine BNNTs. It was found that there is a weak interaction between the sulfonamide and the pristine BNNT with adsorption energy of about −3.1kcal/mol; therefore for this complex any change in the electronic properties is not expected. The sulfonamide adsorbed preferably on the Al and Si dopants from an oxygen atom of SO2 group with adsorption energies of about −28.8 and −14.9kcal/mol, respectively. Despite the highest reactivity of the Al-doped BNNT, its electronic properties were not sensitive to the sulfonamide. The results showed that after adsorption of the sulfonamide on the Si-doped BNNT, the electrical conductivity of BNNT significantly increases. Therefore, the Si-doped BNNT can be a potential candidate for detection of sulfonamide-based drugs. It was predicted that this sensor benefits a short recovery time of about 72ms.

Cyanogen, Methylacetylene, Hydroquinone, Ethylacetylene, Aniline, Pyrrole, and Ethanol detection by using BNNT: DFT studies

Electrical sensitivity of a Boron Nitride Nano Tube (BNNT) was examined toward hydroquinone (C6H4(OH)2), cyanogens (C2N2), methylacetylene (C3H4), ethylacetylene (C4H6), aniline (C6H5NH2), ethanol (C2H5OH), pyrrole (C4H5N), molecules by using Density Functional Theory (DFT) calculations at the B3LYP/6-31G(d) level of theory. In considering the dsorption energy (Ead) of those molecules on the BNNT are sequenced: C6H5NH2(Ead= -47.55kcal/mol)> C4H5N (Ead=-26.66kcal/mol) >C2H5OH(Ead= -25.91kcal/mol)> (CN)2(Ead=-20.70kcal/mol)> C6H4(OH)2(Ead= -20.21kcal/mol) >C3H4(Ead=-12.73kcal/mol)> C4H6(Ead=-11.19kcal/mol). According to this comparison aniline molecule with Ead=-47.55 kcal/mol has the most adsorption energy among all molecules. Calculations showed that when the nanotube was doped by Si and Al atoms, the amount of HOMO/LUMO energy gap (Eg) reduced significantly. This reduced showed that BNNT is a suitable semiconductor after doping and the doped BNNT in the presence of those gases generates an electrical signal and therefore can be used potentially for gas sensors. Recent researches demonstrate that Boron nitride nanotube is a suitable adsorbent for detection and separation of those compounds.

Adsorption of diazinon and hinosan molecules on the iron-doped boron nitride nanotubes surface in gas phase and aqueous solution: A computational study

In this study, the geometric structures and electronic properties of two widely used organophosphorus pesticides, diazinon and hinosan, boron nitride nanotubes (BNNTs) and Fe doped boron nitride nanotubes (FeBNNTs) as adsorbents of these pesticides are studied by density functional theory calculation as well as dispersion correction by Grimme method. The results show that Fe doping in boron nitride nanotubes structures increases the potency of nanotubes to adsorb mentioned pesticides, especially when Fe atom located instead of N atom. Comparing the adsorption energies of diazinon on FeBNNTs with ones for hinosan demonstrate that the adsorption of hinosan is energetically more favorable by FeBNNTs. Assessment of adsorption energies in aqueous solution confirmed significant decrease in their values compared to ones in gaseous phase. However, the adsorption of diazinon and hinosan on both BNNTs and FeBNNTs are exothermic. So, BNNTs and FeBNNTs may be promising candidates as appropriate adsorbents for adsorbing diazinon and hinosan. Also, the results of calculations have revealed that van der Waals interaction energies are remarkably large in adsorption of diazinon and hinosan on all boron nitride nanotubes.

Structural and elastic properties characterization of Be and Mg doped boron nitride nanotubes using DFT calculations

Through doping boron nitride nanotubes, their band gaps could be controlled which results in extending the range of their applications particularly in nanosensors. In this article, the structural and elastic properties of Be and Mg doped boron nitride nanotubes with various chiralities are studied based on ab initio density functional calculations. In order to perform the density functional theory (DFT) calculations, the exchange correlation of Perdew–Burke–Ernzerhof within the generalized gradient approximation (GGA) framework is employed. It is observed that doping Be and Mg atoms increases the equilibrium strain energy of boron nitride nanotubes. Furthermore, it is found that among all of the considered nanotubes, an increase in the value of Young’s modulus of (4,4) armchair boron nitride nanotube through doping Be atom instead of boron atom is so considerable.

Effect of substitutional carbon-doping in BNNTs on HF adsorption: DFT study

We employed density functional calculations to investigate the adsorption behavior of HF gas on the side walls of pure and carbon-doped boron nitride nanotubes (BNNTs). The HF adsorption over the pure BNNT opens a door for its functionalization without causing significant changes in its electronic properties. The substitutional doping of carbon atom on the BNNT considerably enhances its affinity towards HF where the effect of the dopant concentration plays a vital role. The change in electronic properties of the doped BNNT on HF adsorption is significant enough to consider it a potential sensor for HF detection.

Carbon monoxide adsorption on carbon atom doped perfect and Stone–Wales defect single-walled boron nitride nanotubes: a DFT investigation

The CO adsorption on the perfect and defective boron nitride nanotubes (BNNTs) was investigated using the density functional theory at the B3LYP/LanL2DZ theoretical level. The 7-layered armchair (5,5) BNNT doping with C atom on B and N sites was selected for the doped BNNT models, in which the ends of the BNNTs were saturated by hydrogen atoms. The structural and electronic properties of BNNTs and their adsorption configurations with CO were obtained. The binding energies of carbon atom doping on BNNT and adsorption energies of CO molecules on BNNTs were also calculated. The adsorption strength of the CO on BNNT was significantly improved by defective and doped structural creation. The CO adsorption on carbon atom doping on the nitrogen site of Stone–Wales defect BNNT displayed the strongest adsorption with a binding energy of −2.46 kJ/mol.

Carbon dioxide adsorption on doped boron nitride nanotubes

Boron nitride nanotubes are promising structures as far as gas adsorption process is concerned.

Ethyl benzene detection by BN nanotube: DFT studies

Electrical sensitivity of a boron nitride nanotube (BNNT) was examined toward ethyl benzene (C8H10) molecule by using density functional theory (DFT) calculations at the B3LYP/6-31G(d) level, and it was found that the adsorption energy (Ead) of ethyl benzene on the pristine nanotubes is about −11.42kJ/mol. But when nanotubes have been doped with Si, O, S. P atoms, the adsorption energy (Ead) and recovery time changed and the sensitivity of the nanotubes as adsorbent of C8H10 molecule was increased. Calculations showed that when the nanotube is doping, the adsorption energy will be equal to −1.75kJ/mol which leads to a decrease in the recovery time and also, due to doping the nanotube with O, the amount of HOMO/LUMO energy gap (Eg) will reduce significantly. It seems that nanotube (BNNT) is a suitable semiconductor after doping, and the doped BNNT in the presence of ethyl benzene an electrical signal is generating directly and therefore can potentially be used for ethyl benzene sensors, but BNNT is not a suitable adsorbent for C8H10 molecules.

Properties of 5d atoms doped boron nitride nanotubes：a first-principles calculation and molecular orbital analysis

The geometry, electronic structure and magnetic property of boron nitride nanotube (BNNT), whose boron/nitride atoms are substituted by 5d atoms (B5d or N5d), are investigated by first-principles calculations based on density functional theory. The pure-BNNT and BNNT with boron vacancy (VB) or nitrogen vacancy (VN) are also investigated for comparison. Results show that the local symmetry of B5d system is similar to C3v, however the N5d system exhibits a large geometric deviation from C3v. The total magnetic moments of doped systems are different from each other, and B5d system present a strong regularity. The total density of states is presented, where impurity energy levels exist. The impurity energy levels and total magnetic moment can be explained by the molecular orbital theory under C3v symmetry.