First-principles study on α/β/γ-FeB₆ monolayers as potential gas sensor for H₂S and SO₂

Area of Science:

• Materials Science
• Computational Chemistry
• Nanotechnology

Background:

• Investigating toxic gas adsorption on 2D materials is crucial for developing advanced sensors.
• Two-dimensional (2D) iron boride (FeB₆) monolayers offer unique electronic and surface properties for gas interactions.

Purpose of the Study:

• To explore the adsorption behavior of toxic gases sulfur dioxide (SO₂) and hydrogen sulfide (H₂S) on different phases (α/β/γ) of 2D FeB₆ monolayers.
• To evaluate the potential of these FeB₆ monolayers as sensing materials for SO₂ and H₂S detection.

Main Methods:

• Density Functional Theory (DFT) calculations were employed to simulate gas adsorption.
• Key parameters analyzed include adsorption energy, adsorption distance, Mulliken charge, charge density difference, band structure, density of states, work function, and theoretical recovery time.

Main Results:

• H₂S and SO₂ exhibit chemisorption on α/β-FeB₆ monolayers and physisorption on the γ-FeB₆ monolayer.
• The γ-FeB₆ monolayer demonstrates a short recovery time for H₂S and SO₂ at room temperature, indicating suitability for reusable sensors.
• The α/β-FeB₆ monolayers show potential for H₂S sensing at elevated temperatures (500 K) with reduced recovery times.

Conclusions:

• The γ-FeB₆ monolayer is a promising candidate for developing reusable H₂S and SO₂ gas sensors operating at room temperature.
• The α/β-FeB₆ monolayers are also viable for H₂S gas sensing applications, particularly under higher operating temperatures.