Development of Pd/In₂O₃ hybrid nanoclusters to optimize ethanol vapor sensing

Area of Science:

• Materials Science
• Nanotechnology
• Chemical Sensing

Background:

• Development of sensitive and selective ethanol gas sensors is crucial for various applications.
• Indium trioxide (In2O3) is a promising semiconductor material for gas sensing.
• Palladium (Pd) decoration can enhance the catalytic and sensing properties of metal oxide nanostructures.

Purpose of the Study:

• To synthesize palladium-decorated indium trioxide (Pd/In2O3) hybrid nanoclusters (NCs) for high-performance ethanol sensing.
• To investigate the gas-sensing properties of the synthesized Pd/In2O3 NCs towards ethanol vapor.
• To optimize the Pd loading and operating temperature for maximum sensor performance.

Main Methods:

• Synthesis of Pd/In2O3 hybrid nanoclusters using a dual-target cluster beam deposition (CBD) method.
• Fabrication and characterization of a gas sensor based on the synthesized Pd/In2O3 NCs.
• Evaluation of sensor performance including sensitivity, selectivity, response/recovery times, stability, and limit of detection.

Main Results:

• Pd/In2O3 hybrid NCs exhibited excellent sensitivity, stability, and selectivity to low ethanol concentrations.
• Optimal performance was achieved at 260 °C with 6 at% Pd loading, showing a maximum response of 101.2.
• The sensor demonstrated a low limit of detection (24 ppb), high sensitivity (28.24 ppm^-1/2), and rapid response/recovery times (2.7 s / 4.4 s for 100 ppm ethanol).
• Excellent repeatability and stability were observed over 30 days, with high selectivity for ethanol over other VOCs.

Conclusions:

• The synthesized Pd/In2O3 hybrid NCs are highly promising materials for developing advanced ethanol gas sensors.
• The CBD method enables controlled synthesis of nanostructures with enhanced gas-sensing properties.
• Palladium decoration significantly improves the performance of In2O3-based ethanol sensors.