Using first-principles calculations coupled with thermodynamic analysis, we have explored the sensing behavior of the two-dimensional MoSi₂N₄ (2D MSN) monolayer towards selected hazardous gas molecules, such as CO, CO₂, NO, NO₂, SO₂, H₂S, NH₃, CH₄, methanol (CH₃OH), ethanol (C₂H₅OH), and acetone (C₃H₆O). We find that the incident molecules bind weakly (0.13 to 0.36 eV) on pristine monolayer, however the adsorption energies improve significantly (0.38 to 0.86 eV) on the charged MSN monolayer because of the enhanced electrostatic interaction caused by appreciable charge transfers (0.36e to 0.67e). In particular, negatively charged MSN monolayers exhibit a substantial improvement in the adsorption of H₂S and NH₃, while both negatively and positively charged MSN monolayers showed enhanced adsorption towards NO and NO₂. Appropriate adsorption energies are coupled with quantifiable changes in the electronic properties, and variation in the work function of MSN monolayer, which authenticate its potential as efficient nanosensor. Application of thermodynamic analysis further validate the reversible sensing characteristics of MSN monolayer at ambient conditions. Our findings show that gated MSN monolayers can serve as sensitive and selective nanosensors towards common pollutants.

利用第一性原理计算与热力学分析相结合，我们探索了二维 MoSi ₂ N ₄ (2D MSN) 单层对选定危险气体分子（如 CO、CO ₂、NO、NO ₂、SO ₂ ）的传感行为、H ₂ S、NH ₃、CH ₄、甲醇(CH ₃ OH)、乙醇(C ₂ H ₅ OH)和丙酮(C ₃ H ₆ O)。我们发现入射分子在原始单层上的结合较弱（0.13 至 0.36 eV），然而，由于明显的电荷转移（0.36e 至 0.36eV​​）导致静电相互作用增强，带电 MSN 单层上的吸附能显着提高（0.38 至 0.86 eV） 0.67e）。特别地，带负电的MSN单层对H ₂ S和NH ₃的吸附表现出显着的改善，而带负电和带正电的MSN单层都对NO和NO ₂表现出增强的吸附。适当的吸附能与电子特性的可量化变化以及 MSN 单层功函数的变化相结合，这证明了其作为高效纳米传感器的潜力。热力学分析的应用进一步验证了MSN单层在环境条件下的可逆传感特性。我们的研究结果表明，门控 MSN 单层可以作为针对常见污染物的敏感和选择性纳米传感器。