Three-Dimensional Inverse Opal WO₃/g-C₃N₄ Gas Sensor for Accurate and Selective Acetone Detection in Exhaled Breath

Area of Science:

• Materials Science
• Nanotechnology
• Chemical Engineering

Background:

• Metal oxide semiconductors (MOS) are key for chemiresistive gas sensors but suffer from aggregation and poor charge separation.
• Unmodified MOS nanostructures have limited surface area, low porosity, and slow charge migration, hindering gas sensing performance.

Purpose of the Study:

• To develop a highly sensitive and selective gas sensor for acetone detection in exhaled breath.
• To overcome the limitations of unmodified MOS nanostructures by creating a composite material with improved sensing capabilities.

Main Methods:

• Synthesized a three-dimensional inverse opal (3DIO) WO3 composite loaded with graphitic carbon nitride (g-C3N4) using impregnation and sacrificial template methods.
• Investigated the acetone sensing performance of the WO3/g-C3N4 composite.

Main Results:

• The WO3/g-C3N4 composite exhibited excellent acetone sensing, with a response of 7.33 at 10 ppm and a detection limit of 65 ppb.
• The sensor demonstrated favorable selectivity and reliable stability.
• The enhanced performance is attributed to the synergistic effect of the 3D ordered macroporous structure and the n-n heterojunction between WO3 and g-C3N4, facilitating charge transfer.

Conclusions:

• The developed WO3/g-C3N4 composite with a 3D ordered macroporous architecture offers a promising strategy for real-time and accurate acetone detection.
• This approach paves the way for the development of portable breath analysis sensors.