Silicon-doped Boron Nitride Research Articles

Theoretical investigation of ozone adsorption on metal free element doped boron nitride monolayers.

Ozone in the troposphere poses significant environmental and health risks, contributing to global warming and being linked to respiratory diseases, making it critical to find effective methods to remove ozone from the atmosphere. This study investigates the adsorption of ozone on boron nitride (BN) monolayers doped with metal-free elements, specifically carbon, silicon, oxygen, and phosphorus, using first-principles calculations based on Density Functional Theory (DFT). Our results showed that ozone adsorbed on boron nitride doped with carbon exhibited physisorption and had an adsorption energy of -0.272 eV. Ozone adsorbed on silicon-doped boron nitride dissociated into an oxygen atom and an O2 molecule and showed chemisorption with an energy of -8.074 eV. Notably, phosphorus-doped boron nitride dissociated ozone, leading to the release of O2 and bonding of a single oxygen atom to the boron nitride monolayer. These findings highlight how carbon and silicon-doped boron nitride can be useful in removing ozone from the troposphere and the potential of phosphorus-doped boron nitride to adsorb ozone and release a much safer O2 molecule.

Silicon-doped boron nitride graphyne-like sheet for catalytic N2O reduction: A DFT study

In this work, spin-polarized density functional theory calculations are conducted to evaluate the possible applicability of a single Si atom doped boron nitride graphyne-like nansoheet (Si@BN-yne) for reduction of nitrous oxide (N2O). The calculations show that Si-doping in BN graphene is energetically favorable, and the resulting Si@BN-yne is both dynamically and thermodynamically stable. According to our findings, N2O spontaneously dissociates when it interacts with the Si@BN-yne from its O site without the need for an energy barrier, releasing 2.89 eV of energy. The adsorption energy of CO molecule on the Si@BN-yne is less negative than that of N2O, implying that N2O will predominately occupy the catalyst surface. The CO + Oad reaction is used to remove the remaining oxygen atom (Oad) from the Si@BN-yne surface. The calculations show that the reaction proceeds through a low energy barrier of 0.05 eV, which is much lower than the previously reported catalysts. This demonstrates the high catalytic activity of Si@BN-yne nanosheet. Furthermore, the adsorption of H2O and O2 species on the Si@BN-yne nanosheet is investigated. The results show that the presence of these species has no effect on the catalytic activity of the Si@BN-yne for N2O reduction. These results show that the proposed novel Si@BN-yne catalyst can be regarded as an efficient material in the development of promising active catalysts for N2O elimination from the environment.

Enhancement of caffeine adsorption on boron nitride fullerene by silicon doping

The physicochemical interaction between undoped- (B24N36; BNF) and silicon-doped boron nitride (B24N35Si; Si-BNF) fullerenes with caffeine was studied in the frame of the density functional theory (DFT). The influence of chemical composition in the capability of the fullerene to interact with caffeine was analyzed in terms of its structural stability, adsorption energy and charge distribution. The obtained results show that caffeine adsorption is enhanced by Si doping. The adsorption energy of caffeine molecule onto the BNF was calculated to be − 0.26 eV, whereas it was − 0.33 eV after doping. This effect is attributed to a rearrangement of the charge density driven by the substitutional defect (SiN). After caffeine adsorption, an electron density displacement from the Si–BNF to the sorbate which stabilizes the caffeine/Si–BNF system is identified. Moreover, Si doping decreases the chemical hardness, while it induces a net spin angular momentum in the fullerene. The magnetic moment of the Si–BNF was determined in 1.0 µB, which does not vanish after caffeine adsorption. The physicochemical parameters of the Si–BNF, along with its magnetic behavior, could favor using it as nanovehicle for drug delivery.

Epoxidation of ethylene over carbon and silicon-doped boron nitride sheets: A comparative DFT study

Using first-principle calculations, we compare the catalytic activity of the experimentally available C- or Si-doped boron nitride nanosheet (C-/Si-BNNS) towards the epoxidation of ethylene by N2O molecule. The epoxidation reaction of ethylene over these surfaces includes the decomposing of N2O into N2 and an oxygen atom (Oads), formation of the ethyleneoxy intermediate, and the creation of ethylene oxide. Our results show that the catalytic activity of C-BNNS for epoxidation of ethylene is better than Si-BNNS, due to more favorable charge-transfer effects. The results presented here suggest a green, low-cost, and metal-free approach for low-temperature epoxidation of ethylene using C-BNNS.

The Structure and Light Emitting of Silicon-Doped Boron Nitride Nanotubes

In this paper, we report the structural and optical properties of bamboo-like silicon-doped boron nitride nanotubes. The morphologies and structures of the nanotubes were characterized using electron microscopy and FTIR spectroscopy. Three strong broad peaks centered at 1.76ev, 2.20ev, 2.40ev were observed from the room-temperature PL spectrum of the nanotubes. The spectrum suggested the existence of multifold energy levels within the band gap.

A theoretical study of silicon-doped boron nitride nanotubes serving as a potentialchemical sensor for hydrogen cyanide

In order to search for a novel sensor to detect and control exposure to hydrogen cyanide(HCN) pollutant molecule in environments, the reactivities of pristine and silicon-doped(Si-doped) (8, 0) single-walled boron nitride nanotubes (BNNTs) towards the HCNmolecule are investigated by performing density functional theory (DFT) calculations. TheHCN molecule presents strong chemisorption on both the silicon-substituted boron defectsite and the silicon-substituted nitrogen defect site of the BNNT, which is insharp contrast to its weak physisorption on pristine BNNT. A remarkable chargetransfer occurs between the HCN molecule and the Si-doped BNNT as proved bythe electronic charge densities. The calculated data for the electronic densityof states (DOSs) further indicate that the doping of the Si atom improves theelectronic transport property of the BNNT, and increases its adsorption sensitivitytowards the HCN molecule. Based on calculated results, the Si-doped BNNTis expected to be a potential resource for detecting the presence of toxic HCN.

Adsorption of formaldehyde molecule on the pristine and silicon-doped boron nitride nanotubes

The adsorption of formaldehyde (HCOH) molecule on the pristine and silicon-doped (Si-doped) single-walled (8, 0) boron nitride nanotubes (BNNTs) is investigated using density functional theory (DFT) calculations. Compared with the weak physisorption on the pristine BNNT, the HCOH molecule presents strong chemisorption on both silicon-substituted boron defect site and silicon-substituted nitrogen defect site of the BNNT, as indicated by the calculated geometrical structures and electronic properties for these systems. It is suggested that the Si-doped BNNT presents high sensitivity to toxic HCOH. Based on calculated results, the Si-doped BNNT is expected to be a potential novel sensor for detecting the presence of HCOH.

Theoretical Study of the Adsorption of Carbon Monoxide on Pristine and Silicon-Doped Boron Nitride Nanotubes

In order to explore the novel application of boron nitride nanotubes (BNNTs), we investigate reactivities of pristine and silicon-doped (Si-doped) (8,0) single-walled BNNTs towards the CO molecule by performing density functional theory calculations. Compared with weak physisorption on the pristine BNNT, the CO molecule presents strong chemical interaction with the Si-doped BNNT, as indicated by the calculated geometrical structures and electronic properties for these systems. It is suggested that doping BNNTs with silicon is expected to be a suitable strategy for adjusting the properties of BNNTs, and that Si-doped BNNTs are expected to find novel applications in nanotechnology.

Phonon characteristics and photoluminescence of bamboo structured silicon-doped boron nitride multiwall nanotubes

Bamboo structured silicon-doped boron nitride multiwall nanotubes are synthesized via catalyst-assisted pyrolysis of a boron-containing polymeric precursor. The nanotubes are characterized using transmission electron microscopy, x-ray diffraction, Raman, and Fourier-transformed infrared spectroscope. The results suggest that the Si dopants cause significant changes in the structure and phonon characteristics of the nanotubes as compared to pure boron nitride nanotubes. A broad photoluminescence band ranging between 500 and 800nm is observed from the nanotubes, which is attributed to Si dopants. Study on temperature dependence of emission intensity suggests that the thermal activation energy of the nonradiative recombination process is 35meV.