Adsorption of NO₂, SO₂, H₂S, and NH₃ on Os-Doped WSe₂ Monolayers: A First-Principles Study

Area of Science:

• Materials Science
• Computational Chemistry
• Environmental Science

Background:

• Tungsten diselenide (WSe2) is a 2D material with potential applications in gas sensing.
• Industrial waste gases such as nitrogen dioxide (NO2), sulfur dioxide (SO2), hydrogen sulfide (H2S), and ammonia (NH3) pose environmental concerns.
• Developing efficient methods for detecting and mitigating these gases is crucial.

Purpose of the Study:

• To investigate the adsorption properties of industrial waste gases on pristine and Os-doped WSe2 monolayers using DFT calculations.
• To evaluate the potential of Os-doped WSe2 as a gas sensor for specific industrial pollutants.

Main Methods:

• Density Functional Theory (DFT) calculations were employed to model the adsorption processes.
• Analysis of adsorption energy, electronic band structure, density of states, charge transfer, and recovery time.
• Comparison of adsorption characteristics between pure WSe2, Os-modified WSe2, and Os-embedded WSe2.

Main Results:

• Os-doping significantly enhances the gas molecule adsorption ability of WSe2 monolayers compared to pristine WSe2.
• Os-modified WSe2 exhibits superior adsorption energy for NO2, SO2, H2S, and NH3.
• Os-embedded WSe2 demonstrates suitability as a gas sensor for H2S and NH3 at elevated temperatures.

Conclusions:

• Os-doped WSe2 presents improved performance for adsorbing key industrial waste gases.
• Os-embedded WSe2 shows promise as a high-temperature gas sensor for H2S and NH3 detection.
• This study highlights the potential of WSe2-based materials for environmental monitoring and gas sensing applications.