Oxygenated VOC Detection Using SnO₂ Nanoparticles with Uniformly Dispersed Bi₂O₃

Area of Science:

• Materials Science
• Chemical Engineering
• Environmental Science

Background:

• Tin dioxide (SnO2) is a widely used semiconductor material for gas sensing applications.
• Detecting oxygenated volatile organic compounds (VOCs) is critical for environmental monitoring and industrial safety.
• Enhancing the sensing performance of SnO2-based materials remains an active area of research.

Purpose of the Study:

• To investigate the effect of bismuth oxide (Bi2O3) as a foreign additive on SnO2 nanoparticles (NPs) for improved oxygenated VOC detection.
• To explore the synthesis of Bi2O3-loaded SnO2 materials and characterize their sensing properties.
• To elucidate the mechanism behind the enhanced sensing performance.

Main Methods:

• Preparation of Bi2O3-loaded SnO2 materials using the impregnation method followed by calcination.
• Characterization of material interfaces and surface properties.
• Gas sensing measurements at various temperatures (200 °C and 250 °C) towards oxygenated VOCs.
• Oxygen temperature-programmed desorption, catalytic combustion, and temperature-programmed reaction measurements.

Main Results:

• Uniform dispersion of Bi2O3 particles on SnO2 surfaces created abundant Bi2O3/SnO2 interfaces.
• Bi2O3-loaded SnO2 samples exhibited increased surface oxygen ions compared to neat SnO2 NPs.
• The sensor based on 1 mol% Bi2O3-loaded SnO2 (1Bi-L-SnO2) showed significantly higher sensitivity and faster response speed towards oxygenated VOCs.
• Adsorption and partial oxidation were identified as dominant mechanisms during ethanol combustion on the composite materials.

Conclusions:

• Surface functionalization of SnO2 with Bi2O3 effectively enhances its gas sensing performance for oxygenated VOCs.
• The improved sensing is attributed to the increased surface oxygen ions at the Bi2O3/SnO2 interfaces.
• The developed 1Bi-L-SnO2 composite material shows potential for simultaneous detection of total oxygenated VOCs in practical applications.