Functionalization of BN nanosheet with N2H4 may be feasible in the presence of Stone–Wales defect

Following recent experimental works, herein we investigated chemical functionalization of a BN graphene-like sheet with hydrazine (N₂H₄) molecule based on the density functional theory. We found that the functionalization of the pristine sheet is not possible; while the presence of some structural defects such as Stone–Wales is essential to make it feasible. Functionalization energy of the defected sheet is calculated to be in the range of ?6.1 to ?7.4 kcal/mol at B3LYP/6-31G (d) level. Based on the obtained results, the functionalized BN sheet is found to be more soluble in water in comparison with the pristine sheet which is in good agreement with previous experimental reports. Also, it was found that the electronic properties of the defected sheet are slightly changed upon the chemical functionalization.     

Electronic, Energetic, and Geometric Properties of Methylene-Functionalized C60

Chemical functionalization of C₆₀ fullerene with one to six carbene (CH₂) molecule(s) has been investigated using density functional theory. We have found that the reaction is regioselective so that a CH₂ molecule prefers to be adsorbed atop a C–C bond which is shared between two hexagonal rings of the C₆₀, releasing energy of ?3.95 eV. Singly occupied molecular orbital (SOMO) of the CH₂ interacts with LUMO of the C₆₀ via a [2 + 1] cycloaddition reaction. Energy of the reaction and work function of the system are decreased by increasing the number of adsorbed CH₂ molecules. The HOMO/LUMO energy gap of C₆₀ is slightly changed and the electron emission from its surface is facilitated upon the functionalization.     

B12N12纳米笼：潜在的二氧化氮检测传感器

利用密度泛函理论通过计算吸附能量、HOMO/LUMO能隙变化、电荷转移、结构扭曲等研究二氧化氮分子在B12N12纳米笼的吸附．此外,通过计算B₁₂N₁₂的电子结合能、Gibbs自由能、态密度和分子表面的静电势研究其稳定性和其它特性．B₁₂N₁₂纳米笼吸附二氧化氮显示三种构型．B₁₂N₁₂团簇的HOMO/LUMO能隙变化对二氧化氮分子的存在非常敏感,从自由团簇的6.84 eV降为NO₂/团簇稳定团簇的3.23 eV．团簇的导电性被极大地提高,表明B₁₂N₁₂纳米簇可能是潜在的二氧化氮气体分子检测传感器.     

Interaction of small molecules (NO,H2, N2, and CH4) with BN nanocluster surface

Structural Chemistry - The interactions between BN nanocluster of B12N12 and small molecules (H2, NO, N2, and CH4) were investigated by using density functional computations, exploiting the...     

A theoretical study of CO adsorption on aluminum nitride nanotubes

Adsorption of toxic CO molecule on single-walled aluminum nitride nanotubes (AlNNTs) was investigated using density functional theory calculations. A detailed analysis of the energetic, geometry, and electronic structure of various CO adsorptions on the tube exterior surface was performed. In contrast to carbon and BN nanotubes, our results indicated that AlNNTs can strongly interact with CO molecules. The adsorption energy of the most stable configuration was calculated to be about −0.25 eV. The Morokuma–Kitaura decomposition for molecular interaction energies was used to investigate the nature of C–Al bond in the most stable CO–AlNNT complex, demonstrating that electrostatic forces and polarization term are basic factors of attractive interaction between CO and AlNNT. They provide 37.9 and 40.4% of attractive interaction and charge transfer energies make a little contribution to the adsorption energy of CO.     

Ab initio study of NH3 and H2O adsorption on pristine and Na-doped MgO nanotubes

We have investigated, on the basis of density functional theory calculations, the structural and electronic properties of chemical modification of pristine and Na-doped MgONTs with NH₃ and H₂O molecules. We found that the NH₃ and H₂O molecules can be barrierlessly adsorbed on the Mg atom of the tube sidewall along with a charge transfer from the adsorbate to MgONT. The adsorption is chemical in nature with adsorption energies about ?22.3 and ?21.5 kcal/mol for H₂O and NH₃, respectively. The calculated density of state (DOS) shows that the chemical modification of MgONTs with these molecules can be generally classified as certain type of “harmless modification.” In other words, the electronic properties of the MgONT are little changed by the adsorption processes. The substitution of an Mg atom in the tube surface with an Na atom results in a semi-insulator to p-type semiconductor transition based on DOS analysis. It was also found that the doping process reduces the adsorption energies and the electronic properties of Na-doped MgONT is slightly more sensitive toward NH₃ and H₂O molecules, compared with the pristine one.     

Transition metal atom adsorptions on a boron nitride nanocage

We have applied density functional theory within B3LYP and M05 functionals to investigate the chemical functionalization of B₁₂N₁₂ nanocage with 3d transition metal (TM) atoms. Main focuses have been placed on configurations corresponding to the located minima of the adsorbates, corresponding adsorption energies, and the modified electronic properties of the cage. It was shown that there is linear correlation between the adsorption energies of the B3LYP and M05 as the results of M05 are higher than those of B3LYP, about 0.52 eV. Based on calculations, the most stable adsorption site is over the bond shared by a four- and a six-membered ring in the outer surface of cluster, in most cases. Based on the M05 results, the adsorption energies of the Sc, Ti, V, Co, and Fe are relatively high (>1.51 eV) and those of Mn, Ni, and Cu calculated to be in the range of 1.00–1.22 eV. The Cr atom forms a weak bond with a boron atom of the B₁₂N₁₂ cluster, while Zn atom cannot be chemically adsorbed. Charge transfer from metals to cluster ascertained that the B₁₂N₁₂ plays as an electron-trapping center. Inducing certain impurity states within the electron density of states, the TM adsorption significantly reduces the HOMO–LUMO gap of cluster, ranging from 32 to 79 %.     

DFT study on the adsorption and dissociation of hydrogen sulfide on MgO nanotube

The adsorption of a H₂S molecule on the surface of an MgO nanotube was investigated using density functional theory. It was found that H₂S molecule can be associatively adsorbed on the tube surface without any energy barrier or it can be dissociated into –H and –SH species overcoming energy barrier of 4.03–7.77 kcal/mol. The associative adsorption is site selective so that the molecule is oriented in such a way that the sulfur atom was linked to an Mg atom. The HOMO–LUMO energy gap of the tube has slightly changed upon associative adsorption, while they were significantly influenced by dissociation process. Especially, the highest occupied molecular orbital of the tube shifts to higher energies which can facilitate electron emission current from the tube surface. Also, energy gap of the tube dramatically decreased by about 0.93–1.05 eV which influences the electrical conductivity of the tube.