Heteroatoms (Si, B, N, and P) doped 2D monolayer MoS ₂ for NH ₃ gas detection†

Abstract

2D transition metal dichalcogenide MoS ₂ monolayer quantum dots (MoS ₂-QD) and their doped boron (B@MoS ₂-QD), nitrogen (N@MoS ₂-QD), phosphorus (P@MoS ₂-QD), and silicon (Si@MoS ₂-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 NH ₃ gas. The results from electronic properties showed that P@MoS ₂-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@MoS ₂-QD surface, signifying the preferred chemisorption surface for NH ₃ detection. The mechanistic studies provided in this study also indicate that the P@MoS ₂-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 MoS ₂ dopants, specifically the P@MoS ₂-QD surface, as a promising candidate for sensors to detect gas.

Abstract

2D transition metal dichalcogenide MoS ₂ monolayer quantum dots (MoS ₂-QD) and their doped boron (B@MoS ₂-QD), nitrogen (N@MoS ₂-QD), phosphorus (P@MoS ₂-QD), and silicon (Si@MoS ₂-QD) counterparts are proposed as selective sensors for NH ₃ gas.