Heteroatoms (Si, B, N, and P) doped 2D monolayer MoS₂ for NH₃ gas detection

2D transition metal dichalcogenide MoS₂ monolayer quantum dots (MoS₂-QD) and their doped boron (B@MoS₂-QD), nitrogen (N@MoS₂-QD), phosphorus (P@MoS₂-QD), and silicon (Si@MoS₂-QD) surfaces have been theoretically investigated using density functional theory (DFT) computation to understand their mechanistic sensing ability, such as conductivity, selectivity, and sensitivity toward NH₃ gas. The results from electronic properties showed that P@MoS₂-QD had the lowest energy gap, which indicated an increase in electrical conductivity and better adsorption behavior. By carrying out comparative adsorption studies using m062-X, ωB97XD, B3LYP, and PBE0 methods at the 6-311G++(d,p) level of theory, the most negative values were observed from ωB97XD for the P@MoS₂-QD surface, signifying the preferred chemisorption surface for NH₃ detection. The mechanistic studies provided in this study also indicate that the P@MoS₂-QD dopant is a promising sensing material for monitoring ammonia gas in the real world. We hope this research work will provide informative knowledge for experimental researchers to realize the potential of MoS₂ dopants, specifically the P@MoS₂-QD surface, as a promising candidate for sensors to detect gas.