Interaction of NH3_3 gas on α\alpha-MoO3_3 nanostructures −- a DFT investigation

The structural stability, electronic properties and NH$_3$ adsorption properties of pristine, Ti, Zr and F substituted $\alpha$-MoO$_3$ nanostructures are successfully studied using density functional theory with B3LYP/LanL2DZ basis set. The structural stability of $\alpha$-MoO$_3$ nanostructures is discussed in terms of formation energy. The electronic properties of pristine, Ti, Zr and F incorporated $\alpha$-MoO$_3$ nanostructures are discussed in terms of HOMO-LUMO gap, ionization potential and electron affinity. $\alpha$-MoO$_3$ nanostructures can be fine-tuned with suitable substitution impurity to improve the adsorption characteristics of ammonia, which can be used to detect NH$_3$ in a mixed environment. The present work gives an insight into tailoring $\alpha$-MoO$_3$ nanostructures for NH$_3$ detection.Comment: 16 pages, 20 figures, 2 table

Sensing behavior of acetone vapors on TiO2_2 nanostructures --- application of density functional theory

The electronic properties of TiO$_2$ nanostructure are explored using density functional theory. The adsorption properties of acetone on TiO$_2$ nanostructure are studied in terms of adsorption energy, average energy gap variation and Mulliken charge transfer. The density of states spectrum and the band structure clearly reveals the adsorption of acetone on TiO$_2$ nanostructures. The variation in the energy gap and changes in the density of charge are observed upon adsorption of acetone on n-type TiO$_2$ base material. The results of DOS spectrum reveal that the transfer of electrons takes place between acetone vapor and TiO$_2$ base material. The findings show that the adsorption property of acetone is more favorable on TiO$_2$ nanostructure. Suitable adsorption sites of acetone on TiO$_2$ nanostructure are identified at atomistic level. From the results, it is confirmed that TiO$_2$ nanostructure can be efficiently utilized as a sensing element for the detection of acetone vapor in a mixed environment.Comment: 13 pages, 14 figures, 3 table

Nitrogen dioxide and ammonia gas molecules interaction studies on phosphorene nanosheet --- a DFT investigation

The adsorption behaviour of hazardous gas molecules, namely nitrogen dioxide (NO$_2$) and ammonia (NH$_3$), on phosphorene nanosheet (PNS) was explored by means of ab initio technique. To improve the structural solidity of pristine PNS, we have introduced the passivation of hydrogen and fluorine at the terminated edge. The structural solidity of both hydrogen and fluorine passivated PNS is verified in terms of formation energy. The main objective of this research work is to probe NO$_2$ and NH$_3$ gases using PNS as a base sensing material. The adsorption of various preferential adsorption sites of these gas molecules is studied in accordance with the average HOMO-LUMO gap changes, natural-bond-orbital (NBO) charge transfer, HOMO-LUMO gap, and adsorption energy. Notably, the negative value of adsorption energy is found upon the adsorption of NO$_2$ and NH$_3$ on PNS and it is in the range of $-1.36$ to $-2.45$ eV. The findings of the present research work recommend that the hydrogenated and fluorinated PNS can be effectively used as a chemical sensor against NO$_2$ and NH$_3$ molecules.Comment: 15 pages, 21 figures, 2 table

Density Functional Study on Structural Stability and Electronic Properties of Neutral, Anionic and Cationic MgSe Nanostructures

The realistic neutral, cationic and anionic states of pristine and Cr incorporated MgSe nanostructures are optimized and simulated successfully with the help of DFT method along with B3LYP/LanL2DZ basis set. The structural stability of MgSe nanostructures are studied using formation energy, chemical hardness. Point symmetry, dipole moment and chemical potential of neutral, cationic and anionic states of pristine and Cr substituted MgSe nanostructures are also studied. The electronic properties such as ionization potential, electron affinity and HOMO-LUMO gap are determined for pristine and Cr substituted MgSe nanostructures. The present work gives the insights on the structural stability and electronic properties of MgSe nanostructure with the incorporation of Cr atoms and the influence of cationic and anionic charge states on MgSe nanostructures are explored

Investigation on nickel ferrite nanowire device exhibiting negative differential resistance — a first-principles investigation

The electronic property of NiFe$_2$O$_4$ nanowire device is investigated through nonequilibrium Green's functions (NEGF) in combination with density functional theory (DFT). The electronic transport properties of NiFe$_2$O$_4$ nanowire are studied in terms of density of states, transmission spectrum and $I{-}V$ characteristics. The density of states gets modified with the applied bias voltage across NiFe$_2$O$_4$ nanowire device, the density of charge is observed both in the valence band and in the conduction band on increasing the bias voltage. The transmission spectrum of NiFe$_2$O$_4$ nanowire device gives the insights on the transition of electrons at different energy intervals. The findings of the present work suggest that NiFe$_2$O$_4$ nanowire device can be used as negative differential resistance (NDR) device and its NDR property can be tuned with the bias voltage, which may be used in microwave device, memory devices and in fast switching devices.Comment: 12 pages, 8 figure

Exploring the Structural Stability and Electronic Properties of VS2 Nanostructures – a DFT Study

The structural stability and electronic properties of pristine, hydrogenated and chlorinated VS2 nanostructures were investigated using density functional theory. The optimization of VS2 nanostructures were carried out successfully with the help of B3LYP/ LanL2DZ basis set. Initially the structural stability was confirmed using formation energy. The electronic properties were discussed in terms of HOMO-LUMO gap, density of state (DOS) spectrum, electron affinity (EA), and ionization potential (IP). The chemical hardness (CH) and chemical potential (CP) of VS2 nanostructures are also reported. The results will give the insights on structural stability and electronic properties of hydrogenated and chlorinated VS2 nanostructures

A DFT study on structural and electronic properties of Mn substituted CdO nanoclusters

Manganese substituted Cadmium Oxide clusters (Cdn−1OnMn) for n = 2 to 7 were optimized using B3LYP exchange correlation function with LanL2DZ as basis set. Structures such as linear, ring and three dimensional structures were optimized to study the structural stability along with dipole moment, HOMO-LUMO gap, ionization potential, electron affinity, stability factor, binding energy and vibrational intensity. The stability of the structure based on the stability factor, binding energy and vibrational intensity were analyzed and reported. The electronic properties are discussed in terms of HOMO-LUMO gap, ionization potential and electron affinity