Room-Temperature Flexible CNT/Fe₂O₃ Film Sensor for ppb-Level H₂S Detection

Area of Science:

• Materials Science
• Nanotechnology
• Chemical Sensing

Background:

• Carbon nanotubes (CNTs) offer excellent mechanical properties for flexible sensors but lack gas selectivity.
• Hydrogen sulfide (H2S) detection is crucial for environmental and industrial safety.
• Developing room-temperature, selective gas sensors remains a significant challenge.

Purpose of the Study:

• To develop a flexible, room-temperature gas sensor with high selectivity for H2S.
• To investigate the sensing performance of carbon nanotube/amorphous Fe2O3 (CNT/Fe2O3) composites for H2S detection.
• To explore the potential for wearable and portable H2S monitoring devices.

Main Methods:

• Fabrication of CNT/Fe2O3 composite films using a one-step solvent-thermal method.
• Room-temperature gas sensing measurements of the CNT/Fe2O3 films.
• Evaluation of sensor performance including selectivity, response/recovery times, and limit of detection (LOD).
• Testing sensor durability under bending conditions and fabrication into a fiber sensor.

Main Results:

• The CNT/Fe2O3 film sensor demonstrated high selectivity towards H2S with a 55.1% response to 100 ppb H2S.
• Achieved a rapid, reversible response at room temperature (approx. 127 s) and a low LOD of ~2 ppb.
• The sensor maintained good performance under bending and in a fiber format, showing a 18.6% response to 100 ppb H2S.

Conclusions:

• The CNT/Fe2O3 composite is a promising material for flexible, room-temperature H2S gas sensors.
• The developed sensor technology offers potential for wearable and portable H2S detection.
• This work advances the development of flexible electronic devices for environmental monitoring.