First-Principles Study on Bi₂Te₂S Monolayer for Adsorption Performance and Sensing Capability.

Area of Science:

• Materials Science
• Computational Chemistry
• Nanotechnology

Background:

• Two-dimensional (2D) materials offer unique properties for gas sensing applications.
• Bismuth telluride sulfide (Bi2Te2S) is an emerging 2D material with potential for electronic and sensing applications.

Purpose of the Study:

• To investigate the gas sensing capabilities of the 2D Bi2Te2S monolayer for various gas molecules.
• To explore the influence of external electric fields and biaxial strain on the gas adsorption properties of Bi2Te2S.

Main Methods:

• First-principles calculations based on density functional theory (DFT).
• Simulation of adsorption of CH4, Cl2, CO, CO2, H2, H2O, H2S, N2, NH3, NO, NO2, O2, and SO2 on the Bi2Te2S monolayer.
• Analysis of adsorption energies, charge transfer, and electronic structures.

Main Results:

• Bi2Te2S monolayer exhibits a strong affinity for Cl2, O2, NO, and NO2 molecules.
• Gas adsorption on Cl2@Bi2Te2S, O2@Bi2Te2S, and NO2@Bi2Te2S systems is significantly enhanced by external electric fields.
• Horizontal biaxial strain tunes the gas adsorption properties, particularly for O2@Bi2Te2S.

Conclusions:

• The Bi2Te2S monolayer demonstrates excellent potential as a highly sensitive and selective gas sensor for Cl2, O2, NO, and NO2.
• External electric fields and strain provide effective methods for tuning the sensing performance of Bi2Te2S.
• This work provides theoretical insights for developing advanced gas sensing devices based on Bi2Te2S.