Title:Theoretical Investigation of NH3 and NO2 Affinity Towards Boron-nitride Nanosheet: A Dft Study
Volume: 18
Issue: 2
Author(s): Zaheer Abbas*Md. Shahzad Khan*
Affiliation:
- Department of Science and Humanities, Government Engineering College, Magadh University, Jehanabad, Bihar-
804407, India
- Department of Physics, Jamia Millia Islamia (A Central University), New Delhi 110025, India
- Department of Physics, Z. A. Islamia P. G. College, Siwan 841226, Bihar, India
Keywords:
Density functional theory, nanosheet, partial density of states, optical properties, extinction coefficient, charge analysis.
Abstract:
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.
