2D SiP Nanosheets as Efficient and Multi-Time Reversible Nanosensor for Nitrogen-Containing Gases

Herein, we present the structural, electronic, and sensing properties of two-dimensional (2D) SiP nanosheets toward nitrogen-containing gases (NCG) like NH 3, NO, and NO 2 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 NO 2 molecules induces a total magnetic moment of 1 μ B on the nonmagnetic SiP nanosheet, thus making it suitable as a magnetic gas sensor. From the Bader charge analysis, it is observed that the NH 3 molecule behaves as a donor, whereas NO and NO 2 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 NH 3, NO, and NO 2 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 NH 3, NO, and NO 2 gas molecules on the SiP nanosheet. Therefore, we suggest a SiP nanosheet as an efficient, fast, and multi-time reusable nanosensor toward NCGs like NH 3, NO, and NO 2 . Our study highlights the potential applications of the SiP nanosheet as a chemical and magnetic gas sensor for NCGs.