Room-Temperature QCM Sensor Based on GO@WO₃ Nanocomposites for Ammonia Detection.

Area of Science:

• Materials Science
• Nanotechnology
• Chemical Sensing

Background:

• Ammonia (NH3) detection is vital for environmental monitoring, industrial safety, and disease diagnosis.
• Room-temperature sensors are highly desirable for practical applications.
• Graphene oxide (GO) and tungsten oxide (WO3) quantum dots (QDs) are promising materials for gas sensing.

Purpose of the Study:

• To develop a novel room-temperature ammonia sensor.
• To enhance ammonia sensing performance using a composite material.
• To investigate the sensing mechanism of the composite material.

Main Methods:

• Fabrication of a sensor using graphene oxide (GO) and WO3 quantum dots (QDs).
• Characterization of the GO@WO3 nanocomposite material.
• Testing the sensor's performance for ammonia detection at room temperature, including sensitivity, response time, selectivity, and stability.

Main Results:

• The GO@WO3 nanocomposite sensor demonstrated significantly enhanced performance compared to pure WO3 QDs.
• A frequency shift of 578 Hz was observed for 10 ppm NH3, 6.4 times higher than the pure WO3 QDs sensor.
• A theoretical limit of detection (LOD) of 60 ppb was achieved, enabling ppb-level NH3 detection with good long-term stability.

Conclusions:

• The developed GO@WO3 nanocomposite sensor offers a simple, efficient, and practical solution for room-temperature ammonia detection.
• The enhanced performance is attributed to the ohmic contact between GO and WO3, facilitating charge transfer and oxygen adsorption.
• This work presents significant advantages over traditional single-component sensors for ammonia monitoring.