Herein, we present the structural, electronic, and sensing
properties
of two-dimensional (2D) SiP nanosheets toward nitrogen-containing
gases (NCG) like NH3, NO, and NO2 using density
functional theory (DFT) calculations. All of the gas molecules are
found to be physisorbed on the surface of the SiP nanosheet, as confirmed
by the small values of adsorption energy. The exposure of NO and NO2 molecules induces a total magnetic moment of 1 μB on the nonmagnetic SiP nanosheet, thus making it suitable
as a magnetic gas sensor. From the Bader charge analysis, it is observed
that the NH3 molecule behaves as a donor, whereas NO and
NO2 molecules behave as acceptors. Very short recovery
times (τ) of 2.28 × 10–9, 7.78 ×
10–5, and 1.71 × 10–3 s for
NH3, NO, and NO2 gas molecules, respectively,
on the SiP nanosheet are observed, thus indicating its fast, reversible,
and multi-time reusable behavior. Further, for the real-world applications
of NCGs@SiP, we investigated the current–voltage (I–V) characteristics and zero-bias transmission
spectra using nonequilibrium Green’s function (NEGF) formalism.
A substantial variation in the current is observed upon exposure of
NH3, NO, and NO2 gas molecules on the SiP nanosheet.
Therefore, we suggest a SiP nanosheet as an efficient, fast, and multi-time
reusable nanosensor toward NCGs like NH3, NO, and NO2. Our study highlights the potential applications of the SiP
nanosheet as a chemical and magnetic gas sensor for NCGs.