An investigation of the positive effects of doping an Al atom on the adsorption of CO2 on BN nanosheets: a DFT study.

This paper presents the results of a study on CO and NO adsorption on SiGe nanoribbons, conducted using density functional theory with the VASP quantum simulation program. The results indicate a slight change in the Si-Ge bond length following CO and NO adsorption. While the buckling changes slightly with CO adsorption (approximately 0.034 Å), it shows a significant increase after NO adsorption (0.453 Å). Electronically, the findings demonstrate that CO adsorption widens the band gap, whereas NO adsorption modifies the original structure’s properties from semiconducting to metallic. SiGe nanoribbons exist with a band gap of 0.2484 eV according to GGA-PBE calculation, 0.3412 eV according to HSE06 calculation; after CO adsorption, these values are 0.3412 eV and 0.4199 eV, respectively. The study also reveals relative charge transfer and variations in the intensity of π and σ bonds after adsorption. Optically, CO adsorption leads to changes in the light absorption and reflection properties; light is most strongly absorbed is between 3–4 eV, while light is most strongly reflected in the energy range of 4–5 eV. In contrast, NO adsorption renders the material structure transparent, allowing almost all light to pass through. These changes show that SiGe nanoribbons are suitable for CO and NO gas sensors; especially for NO, with a sensitivity when adsorbing NO gas up to almost 100%.

Carbon-doped boron nitride nanosheets as highly sensitive materials for detection of toxic NO and NO2 gases: A DFT study

Background: Two-dimensional (2D) nanosheets have been widely explored for sensing toxic gases by investigating structural and electronic properties. However, the optical investigation could be an alternative approach to address the sensing capability of the nanosheets. In the present work, the electronic and optical investigation is performed using density functional theory (DFT) to find out the sensitivity of boron-nitride nanosheet (BNNS) towards NH3 and NO2 gas molecules. Electronic investigation suggests a weak binding of NH3 and NO2 with the 2D sheet, with appreciable changes in the BNNS electronic density of state (DOS) on NO2 interaction. NH3 interaction could not affect the BNNS DOS except for lowering of band dispersion graph across the Fermi level. NO2 interaction brings a noticeable change in spectra, primarily red-shift. Based on this information, tuning is also observed in different optical descriptors, i.e., dielectric constant, refractive index, and extinction coefficient of NO2 interacted BNNS. All these findings advocate sensitivity toward the gas molecule of the 2D sheet could be realized from the optical frame. Objective: Finding NH3 and NO2 affinity of Boron-Nitride Nanosheet Through Optical Spectrum: A DFT Study. Methods: The calculations are performed in the framework of density functional theory (DFT) using Troullier Martins’s norm-conserving pseudo-potential. Results: The NO2 interacted BNNS shows the optical spectra get red-shifted, and the primary reason is the available NO2 molecular state below the fermi level as shown in PDOS analysis. Conclusion: The present investigation predicted an almost similar ε2 spectra pattern of BNNS and NH3-BNNS except in shallow region 7 eV-10 eV; a weak absorption band appeared in this region after NH3 absorption. The main concern for this deviation is the electronic transitions taken from the valance N-p-state of NH3 to the conduction band (primarily π* in nature) of BNNS.

In this ongoing research work, a density functional theory (DFT) study has been performed to investigate the structural, chemical, electrical, and optical properties of the boron nitride nanosheets (BNNSs) by replacing one boron atom from BNNSs with valency comparable Cobalt (Co) and Phosphorus (P) atoms. The order of the calculated cohesion energy is −5.96 > −5.82 > −5.81 eV, respectively, for BN, Co@BN and P@BN, which leads to good structural stability. The calculated Eg follows the order 6.82 > 5.84 > 3.82 eV respectively for BN, P@BN and Co@BN, which reveal evidence of enhancing the electrical properties of the doped structures. Vibrational spectroscopies, global descriptors-DFT parameters, DOS, MEP and absorption spectra gave details information about the enhancement of the various properties of the BN nanosheets by doping, and suggest a high range of application in technology.

Defected boron nitride nanosheet as an electronic sensor for 4-aminophenol: A density functional theory study

A great concern exists about the lifetime, cost, low-temperature performance, and safety of Li-ion batteries. Na-ion batteries (NIB) are an alternative to the Li-ion batteries due to the wide availability of sodium, its low cost, and nontoxicity. Here, we examined the Na and Na+ adsorption on nanosheets of carbon (graphene), AlN, BN, and SiC to explore their potential use as an anode in NIBs. The interaction of atomic Na was found to play the main role in producing different nanosheet cell voltages. Unlike the graphene and SiC nanosheets, the lone pairs on the surface of the AlN and BN nanosheets hinder the Na adsorption and significantly increase the cell voltage. The order of magnitude of the nanosheet cell voltage as an anode in NIBs is as follows: AlN (1.49V) > BN (1.46V) > > C (0.69V) > SiC (0.61V). The AlN and BN nanosheets may be appropriate compounds for NIBs and their cell voltages are comparable with carbon nanotubes.

Structure and Stability of (CeO2)n0,±1 (n=1-3) Clusters towards the Adsorption and Co-adsorption of CO and H2O from DFT Study

Adsorption of the pollutant gas CO on B12P12 nanocage surface is studied through density functional calculations. HOMO and LUMO energy levels, binding energies and  energy bond gaps of three possible configurations of CO on pristine B12P12  has been calculated by means of B3LYP and M062X functional with 6-31g+ basis set. The results showed that there is none or very slight adsorption of CO molecule by pristine B12P12.To overcome the fault, CO adsorption is investigated on Al and N doped B12P12 nanocage with the same method and basis set. The electronic and structural parameters like HOMO and LUMO energy levels and binding energies of possible configurations are calculated and showed that doped B12P12 with both Al and N atoms have increased about % 1.7 with CO molecule which also indicates more Vander Waals attraction between CO and Al and N doped B12P12 nanocage.

Bromochlorodifluoromethane interaction with pristine and doped BN nanosheets: A DFT study

Adsorption of estrone with few-layered boron nitride nanosheets: Kinetics, thermodynamics and mechanism

Gas chromatographic kinetic study of carbon monoxide oxidation over platinum–rhodium alloy catalysts

CO adsorption on the Ni2Pb/Ni(1 1 1) surface alloy: A DFT study

Identifying Key Descriptors for the Single-Atom Catalyzed CO Oxidation

In the present work, density functional theory calculations are used to investigate the healing mechanism of a N‐vacancy defect in boron nitride nanosheet (BNNS) or nanotube (BNNT) with a CH2 molecule. The healing process starts with the chemisorption of CH2 at the defect site, followed by its dehydrogenation over the surface. Next, a H2 molecule is produced which can be easily released from the surface due to its small adsorption energy. For the dehydrogenation of CH2 molecule over the defective BNNS or BNNT, the first CH bond dissociation is the rate determining step. Our results indicate that the dehydrogenation of CH2 over BNNS is both thermodynamically and kinetically more favorable than over BNNT. Besides, this study proposes a novel method for achieving C‐doped BNNSs and BNNTs. Given that the healing process proceeds without using a metal catalyst, therefore, no any purification is needed to remove the catalyst.

A theoretical study has been conducted onto the pristine, Nb-, and Au-doped boron nitride (BN) nanosheets using DFT calculations with the B3LYP-D3 method in order to evaluate their stabilities and electronic properties. The interaction of the guanine molecule with these clusters was also examined in order to determine their adsorption properties. The calculations show that the HOMO-LUMO energy gap (Eg) of the BN nanosheet was strongly decreased upon its doping with Nb and Au atoms, implying a strong enhancement in its surface reactivity. The interaction of the guanine with the BN nanosheet was found to be weak, which leads a slight variation in its energy gap; therefore, a low sensitivity of this nanosheet toward the guanine molecule was observed. The guanine adsorption over the NbBN cluster is very strong, and the calculated adsorptions energies are in the range of −36.7 to −60.2 kcal mol−1, suggesting a great chemical adsorption. For the AuBN cluster, the guanine molecule has been chemisorbed onto its surface with adsorption energies which vary from −24.2 to −38.4 kcal mol−1, which are lower than those obtained for the NbBN cluster. Upon adsorption process, the energy gap of the NbBN cluster was greatly increased, which leads to a decrease in its electrical conductivity; thereby, it cannot be a suitable sensor for the detection of the guanine molecule. On the contrary, the energy gap of the AuBN cluster was reduced by the effect of the guanine adsorption on its surface, indicating an increase in its electrical conductivity; thus, the AuBN cluster possesses a great electronic sensitivity to the guanine molecule. Based on the transition state theory, the recovery time of the guanine desorption from the AuBN cluster was estimated of 27.6 s, reflecting that the Au-doped BN nanosheet could be employed as an appropriate nanosensor for the guanine molecule detection with a short recovery time.