Three-dimensional, millimeter-scale semiconducting SWCNT aerogels for highly sensitive ozone detection

Area of Science:

• Materials Science
• Nanotechnology
• Chemical Sensing

Background:

• Porous semiconducting frameworks are crucial for detecting hazardous gas molecules.
• Single-walled carbon nanotubes (SWCNTs) offer unique electronic properties for sensor applications.

Purpose of the Study:

• To develop millimeter-scale, three-dimensional semiconducting SWCNT (s-SWCNT) aerogels.
• To enhance the gas sensing capabilities of s-SWCNT aerogels through controlled electrical breakdown.

Main Methods:

• Fabrication of millimeter-scale, 3D s-SWCNT aerogels.
• Electrical breakdown process to deactivate metallic SWCNT (m-SWCNT) networks.
• Characterization of aerogel properties, including specific surface area and response to ozone.

Main Results:

• Achieved an on-off ratio of 205 for modulated s-SWCNT aerogels, an 18.9-fold increase.
• Demonstrated high sensitivity for ppb-level ozone detection with a large specific surface area (1270 m² g⁻¹).
• Observed a 1310% increase in response magnitude to 30 ppb ozone compared to pristine SWCNT aerogels.

Conclusions:

• The modulated s-SWCNT aerogels exhibit excellent performance for ppb-level ozone detection.
• The aerogels show rapid detection (3 ppb within 40 s) and long-term stability (200 cycles over 100 h).
• These aerogels are promising candidates for highly sensitive and stable environmental gas sensors.