Low-temperature H₂S detection using Fe-doped SnO₂/rGO nanocomposite sensor.

Area of Science:

• Materials Science
• Nanotechnology
• Chemical Sensing

Background:

• Hydrogen sulfide (H2S) is a toxic and corrosive gas requiring sensitive detection.
• Developing efficient low-temperature gas sensors is crucial for safety and environmental monitoring.
• Metal oxide semiconductors and reduced graphene oxide (rGO) offer promising sensing properties.

Purpose of the Study:

• To design and fabricate a low-temperature H2S gas sensor using a 3% Fe-doped SnO2/rGO nanocomposite.
• To investigate the structural, morphological, and gas sensing properties of the developed nanocomposite.
• To evaluate the sensor's performance, including sensitivity, selectivity, response time, and operating temperature.

Main Methods:

• Fe-doped SnO2 quantum dots (QDs) were synthesized via sol-gel combustion.
• The Fe-SnO2/rGO nanocomposite was formed using a sonication process.
• Comprehensive characterization included XRD, FE-SEM, HRTEM, Raman, XPS, and BET surface area analysis.
• Gas sensing performance was tested at temperatures from 25°C to 175°C.

Main Results:

• The Fe-SnO2/rGO nanocomposite exhibited a well-defined tetragonal SnO2 crystal structure with high integrity.
• BET analysis showed a specific surface area of 72.7 m²/g and a pore size of 7.83 nm.
• HR-TEM confirmed uniform dispersion of 5.6 nm Fe-doped SnO2 QDs on the rGO surface.
• The sensor demonstrated a significant response (42.4) to 10 ppm H2S at 100°C with a 21-second response time.
• Excellent selectivity for H2S over NH3, LPG, and CO was observed.

Conclusions:

• The 3% Fe-doped SnO2/rGO nanocomposite is an effective material for low-temperature H2S gas sensing.
• The rGO incorporation significantly enhances the sensitivity and selectivity of the sensor.
• Synergistic effects between Fe-SnO2 and rGO contribute to the improved gas sensing performance.