Cu-Doped MoSi₂ N₄ Monolayer as a Potential NH₃ Sensor

Area of Science:

• Materials Science
• Computational Chemistry
• Nanoscience

Background:

• Development of sensitive and selective gas sensors is crucial for environmental monitoring and industrial safety.
• Two-dimensional materials offer unique electronic properties for sensing applications.
• Molybdenum Disilicide Nitride (MoSi2N4) is a promising 2D material with potential gas sensing capabilities.

Purpose of the Study:

• To investigate the adsorption performance of various gas molecules on a copper-doped MoSi2N4 monolayer.
• To evaluate the potential of Cu-MoSi2N4 as a sensor for specific gases using theoretical calculations.
• To determine the feasibility of using Cu-MoSi2N4 for ammonia (NH3) detection.

Main Methods:

• Utilized density functional theory (DFT) combined with non-equilibrium Green's function (NEGF) methods.
• Analyzed the electronic transport properties of the Cu-MoSi2N4 monolayer.
• Simulated the adsorption of common gas molecules including O2, N2, CO, NO, NO2, CO2, SO2, H2O, NH3, and CH4.

Main Results:

• The Cu-MoSi2N4 monolayer exhibited high sensitivity to CO, NO, NO2, and NH3 molecules.
• Only NH3 demonstrated moderate adsorption strength (-0.55 eV) on the Cu-MoSi2N4 monolayer.
• NH3 desorption occurred at room temperature with a calculated time of 2.36×10^-3 s, indicating reversibility.

Conclusions:

• The Cu-MoSi2N4 monolayer is a promising candidate for developing ammonia (NH3) gas sensors.
• The material's electronic properties facilitate sensitive detection of specific gas molecules.
• The moderate adsorption and desorption characteristics of NH3 suggest practical sensor applications.