Fast-response MEMS xylene gas sensor based on CuO/WO₃ hierarchical structure

Area of Science:

• Materials Science
• Nanotechnology
• Chemical Engineering

Background:

• Metal oxide semiconductors are crucial for gas sensing applications.
• Developing hierarchical nanostructures can improve gas sensor performance.
• Xylene detection is important for environmental monitoring and safety.

Purpose of the Study:

• To synthesize CuO/WO3 hierarchical hollow microspheres.
• To evaluate the gas sensing performance of these microspheres for xylene detection.
• To investigate the effect of the CuO/WO3 heterojunction on sensor properties.

Main Methods:

• Ultrasonic-wet chemical etching and pyrolysis were used for material synthesis.
• Micro-Electro-Mechanical System (MEMS) technology was employed for sensor fabrication.
• Gas sensing performance was tested by exposing sensors to xylene vapor.

Main Results:

• The CuO/WO3 microspheres exhibited enhanced xylene sensing compared to pristine WO3.
• The CuO/WO3-3 sensor (3% CuO) showed the fastest response-recovery speed and highest response.
• The CuO/WO3-3 sensor demonstrated excellent selectivity and long-term stability.

Conclusions:

• The 3D hierarchical structure and p-n heterojunction of CuO-WO3 significantly improve gas sensing properties.
• The CuO/WO3-3 sensor shows great potential for rapid and reliable xylene detection and monitoring.