Preparation and Gas-Sensitive Properties of SnO₂@Bi₂O₃ Core-Shell Heterojunction Structure.

Area of Science:

• Materials Science
• Chemical Engineering
• Sensor Technology

Background:

• Developing advanced semiconductor materials for gas sensing is crucial for environmental monitoring and safety.
• Tin oxide (SnO₂) and bismuth oxide (Bi₂O₃) are known for their gas-sensing properties, but their combination in a core-shell structure offers synergistic benefits.

Purpose of the Study:

• To design and synthesize a SnO₂@Bi₂O₃ core-shell heterojunction.
• To investigate the structural, morphological, and gas-sensitive properties of the synthesized material.
• To evaluate its performance for ethanol gas detection.

Main Methods:

• Hydrothermal synthesis method was employed to create the SnO₂@Bi₂O₃ core-shell structure.
• X-ray diffraction (XRD), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS) were used for characterization.
• Gas sensitivity tests were conducted at an optimal operating temperature of 300 °C.

Main Results:

• The SnO₂@Bi₂O₃ core-shell structure was successfully synthesized, with Bi₂O₃ content increasing with hydrothermal temperature.
• The optimal composite, prepared at 160 °C, showed a response value of 19.7 to 100 ppm ethanol.
• The sensor exhibited a fast response time of 4 s and good repeatability for ethanol detection.

Conclusions:

• The SnO₂@Bi₂O₃ core-shell heterojunction demonstrates excellent gas-sensitive performance towards ethanol.
• The p-n heterojunction properties are attributed to the enhanced gas sensing capabilities.
• This material holds promise for the development of high-performance ethanol gas sensors.