Silver-atom catalysts boosted nitrogen-doped MoS2 for chemiresistive NO2 gas sensor

MoS₂ has elicited notable interest as a promising material for gas sensing applications. The pristine MoS₂ is still encumbered by drawbacks such as low response, large response time, and a propensity for weak adsorption of target gases, which can impede its effectiveness in practical applications. To address these challenges, this study investigates the functionalization of nitrogen-doped MoS₂ with silver nanoparticles to improve its sensing performance for NO₂ gas. MoS₂ nanosheets were synthesized through chemical vapor deposition and subsequently subjected to nitrogen plasma treatment to facilitate doping. We evaluated the gas sensing performance of pristine MoS₂, Ag-decorated MoS₂, nitrogen-doped MoS₂, and Ag-decorated nitrogen-doped MoS₂ (Ag-N-MoS₂) specifically for NO₂ gas sensing. The Ag-N-MoS₂ configuration demonstrated a response that was nearly double that of pristine MoS₂ at 100 °C, demonstrating the benefits of this dual enhancement strategy. Additionally, selectivity tests revealed the sensor's capacity to distinguish NO₂ from other gases. To reinforce our experimental results, density functional theory (DFT) calculations were conducted, confirming the improved electronic properties achieved through nitrogen doping and Ag NP functionalization. This research underscores the potential of Ag-N-MoS₂ as a formidable platform for sophisticated gas sensors, addressing crucial environmental monitoring requirements while surmounting the intrinsic limitations of pristine MoS₂.