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First-Principles Study of Hazardous Gas Molecule Adsorption on Janus MoSTe Monolayer Modified with Surface Vacancy
Yuhui Zhu1, Sheng Xu1, Qiang Wang1
1School of Metallurgy Engineering, Jiangsu University of Science and Technology, Zhangjiagang 215600, China.
Nanomaterials (Basel, Switzerland)
|May 26, 2026
Summary
Vacancy defects in Janus MoSTe monolayers enhance sensitivity for hazardous gas detection. This study reveals tailored adsorption properties, crucial for developing advanced gas sensors for environmental and industrial safety.
Area of Science:
- Materials Science
- Surface Science
- Computational Chemistry
Background:
- Highly sensitive two-dimensional (2D) gas-sensing materials are vital for environmental monitoring, industrial safety, and climate protection.
- Janus MoSTe monolayers offer potential as novel 2D gas sensors due to their unique structure.
Purpose of the Study:
- To investigate the adsorption and sensing properties of hazardous gases (NO, NO2, F2, Cl2) on pristine and defective Janus MoSTe monolayers.
- To explore the impact of sulfur (S) and tellurium (Te) vacancies on the electronic and adsorption characteristics of MoSTe.
Main Methods:
- Density Functional Theory (DFT) calculations were employed to model gas molecule adsorption.
- Analysis of adsorption energies, distances, charge transfers, and electronic structures (band gaps).
Main Results:
- Vacancy introduction significantly enhances adsorption energies and charge transfer, altering adsorption from physisorption to chemisorption for certain gases.
- S vacancies promote chemisorption of NO, NO2, and Cl2, while Te vacancies induce strong physisorption of NO and NO2.
- Gas adsorption modulates the band gap, with F2 and Cl2 adsorption on pristine MoSTe converting an indirect to a direct band gap.
- O2 adsorption on defective MoSTe suggests limitations under atmospheric conditions.
Conclusions:
- Vacancy-defective Janus MoSTe monolayers show promise for detecting specific hazardous gases.
- Theoretical insights guide experimental efforts in designing advanced 2D gas-sensing materials.
- The study highlights the importance of vacancy engineering for tuning gas adsorption properties.
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