Doping Strategy of Monolayer MoS2 to Realize the Monitoring of Environmental Concentration of Desflurane: A First-Principles Study

Abstract

Desflurane is a new volatile inhalation anesthetic that is widely used in medical operation. However, various diseases can be caused by chronic exposure to desflurane, which is also a greenhouse gas. Therefore, it is urgent to find a suitable method for monitoring desflurane. In this paper, the process of doping of Pd, Pt, and Ni on the MoS₂ surface is simulated to determine the stability of the doping structure based on first-principles. The adsorption properties and sensing properties of Pd-MoS₂, Pt-MoS₂, and Ni-MoS₂ on desflurane are explored by parameters including independent gradient model based on Hirshfeld partition (IGMH), electron localization function (ELF), and density of states (DOS), sensibility, and recovery time, subsequently. The doping results show that the three doping systems (Pd-MoS₂, Pt-MoS₂, and Ni-MoS₂) are structurally stable, and the chemical bonds are formed with MoS₂. The adsorption results show the best chemisorption between Pt-MoS₂ and desflurane with the chemical bonds between them. The results of IGMH, ELF, and DOS also confirm it. The sensing characterization results show that the recovery time of Pt-MoS₂ ranges between 85.27 and 0.027 s, and the sensitivity ranges from 99.26 to 25.69%, all of which can meet the requirements of the sensor. Considering the adsorption effect and sensing characteristics, Pt-MoS₂ can be used as a gas-sensitive material for detecting the concentration of desflurane.

Figure 1

Molecular structure of (a) MoS₂ and (b) C₃H₂OF₆.

Figure 2

Phonon band structure of (a) MoS₂, (b) Ni-MoS₂, (c) Pt-MoS₂, and (d) Pd-MoS₂.

Figure 3

Most stable configuration and results of CDD and IGMH in (a) Pd-MoS₂, (b) Pt-MoS₂, and (c) Ni-MoS₂. The CDD and IGMH isovalues of C₃H₂OF₆/Pd-MoS₂, C₃H₂OF₆/Pt-MoS₂, and C₃H₂OF₆/Ni-MoS₂ is 0.01 au. Green is for electron dissipation regions, and blue is for electron accumulation regions in CDD. Blue is for attraction, and green is for repulsion in IGMH.

Figure 4

Scatter plot of IGMH in (a) Pd-MoS₂, (b) Pt-MoS₂, and (c) Ni-MoS₂.

Figure 5

Charge density along the Z axis in each system.

Figure 6

Energy change during the adsorption process in (a) Pd-MoS₂, (b) Pt-MoS₂, and (c) Ni-MoS₂.

Figure 7

DOS and PDOS of (a) Pd-MoS₂, (b) Pt-MoS₂, and (c) Ni-MoS₂.

Figure 8

Most stable adsorption configuration and results of CDD and IGMH in (a) C₃H₂OF₆/Pd-MoS₂, (b) C₃H₂OF₆/Pt-MoS₂, and (c) C₃H₂OF₆/Ni-MoS₂. The CDD isovalues of C₃H₂OF₆/Pd-MoS₂, C₃H₂OF₆/Pt-MoS₂, and C₃H₂OF₆/Ni-MoS₂ are 0.01, 0.01, and 0.001 au, respectively. The IGMH isovalue of C₃H₂OF₆/Pd-MoS₂, C₃H₂OF₆/Pt-MoS₂, and C₃H₂OF₆/Ni-MoS₂ is 0.01 au.

Figure 9

Scatter plot of IGMH in (a) C₃H₂OF₆/Pd-MoS₂, (b) C₃H₂OF₆/Pt-MoS₂, and (c) C₃H₂OF₆/Ni-MoS₂.

Figure 10

DOS and PDOS of (a) C₃H₂OF₆/Pd-MoS₂, (b) C₃H₂OF₆/Pt-MoS₂, and (c) C₃H₂OF₆/Ni-MoS₂.

Figure 11

ELF of (a) C₃H₂OF₆/Pd-MoS₂, (b) C₃H₂OF₆/Pt-MoS₂, and (c) C₃H₂OF₆/Ni-MoS₂.

Figure 12

Work functions of each adsorption system.

Figure 13

Band structure of (a) Pd-MoS₂, (b) Pt-MoS₂, (c) Ni-MoS₂, (d) C₃H₂OF₆/Pd-MoS₂, (e) C₃H₂OF₆/Pt-MoS₂, and (f) C₃H₂OF₆/Ni-MoS₂.

Figure 14

Sensitivity and recovery time of Pd-MoS₂, Pt-MoS₂ and Ni-MoS₂ to C₃H₂OF₆ under different temperature. The bar and dotted line graphs indicate sensitivity and recovery time, respectively.