Room Temperature Humidity Tolerant Xylene Sensor Using a Sn-SnO₂ Nanocomposite

Area of Science:

• Materials Science
• Nanotechnology
• Environmental Science

Background:

• Xylene is a significant indoor air pollutant affecting human health.
• Detecting non-polar and less reactive xylene at room temperature is challenging.

Purpose of the Study:

• To develop a sensitive room-temperature sensor for xylene detection.
• To synthesize a metallic tin-doped Sn-SnO2 nanocomposite for enhanced gas sensing.

Main Methods:

• A simple solvothermal route was used to synthesize Sn-SnO2 nanocomposite.
• The sensor's performance was evaluated for xylene and other VOCs under varying humidity.
• Characterization of the nanocomposite morphology and surface area was performed.

Main Results:

• The Sn-SnO2 nanocomposite exhibited uniform Sn nanoparticles within SnO2 nanospheres (∼70 nm) with a high surface area (118.8 m²/g).
• The sensor showed a strong affinity for benzene, toluene, ethylbenzene, and xylene (BTEX), with the highest response to xylene.
• A linear response to xylene (1-100 ppm) was observed at room temperature, with a sensitivity of ∼255% at 60 ppm, a response time of ∼1.5 s, and a recovery time of ∼40 s.
• The sensor demonstrated minimal interference from humidity variations (40-70%).

Conclusions:

• The mesoporous nanosphere morphology facilitates VOC diffusion.
• Metallic tin enhances the affinity for xylene at room temperature.
• The nanocatalytic Sn-SnO2 nanocomposite is an effective material for sensing indoor pollutants under humid conditions.