High Performance H₂S Sensor Based on Ordered Fe₂O₃/Ti₃C₂ Nanostructure at Room Temperature.

Area of Science:

• Materials Science
• Nanotechnology
• Chemical Sensing

Background:

• Traditional metal oxide gas sensors often require elevated temperatures for operation.
• Heterogeneous nanojunctions offer enhanced gas sensing capabilities.
• Hydrogen sulfide (H2S) is a toxic gas requiring sensitive detection methods.

Purpose of the Study:

• To develop a novel room-temperature H2S gas sensor using Fe2O3 functionalized Ti3C2 MXene.
• To evaluate the gas sensing performance of the Fe2O3/Ti3C2 composite for H2S detection.
• To investigate the underlying mechanisms responsible for the enhanced sensing performance.

Main Methods:

• Synthesis of Fe2O3 functionalized Ti3C2 MXene.
• Fabrication of a gas sensor device.
• Gas sensing performance testing at room temperature.
• Density Functional Theory (DFT) calculations for adsorption energy analysis.

Main Results:

• The Fe2O3/Ti3C2 sensor demonstrated a broad detection range (0.01-500 ppm) and a low detection limit (10 ppb) for H2S.
• Rapid response (10 s) and recovery (15 s) times were achieved at room temperature.
• DFT calculations confirmed stronger H2S adsorption on Fe2O3/Ti3C2 compared to pure Fe2O3 or Ti3C2.
• Enhanced surface area, abundant functional groups, and efficient electron transfer contributed to superior sensing performance.

Conclusions:

• Fe2O3 functionalized Ti3C2 MXene is a promising material for highly sensitive, room-temperature H2S gas sensing.
• The nanojunction design significantly improves gas absorption, adsorption, and electron transfer.
• This material offers potential for practical applications in ppb-level H2S monitoring.