Pd-Sensitized In₂Se₃ Films Boost Low-Concentration H₂ Detection

Area of Science:

• Materials Science
• Chemical Engineering
• Sensor Technology

Background:

• Chemiresistive sensors face challenges in detecting hydrogen (H₂) at room temperature (RT).
• Indium selenide (In₂Se₃) films are typically sensitive to nitrogen dioxide (NO₂) but not H₂.

Purpose of the Study:

• To synthesize and integrate palladium-sensitized In₂Se₃ (Pd-In₂Se₃) films for effective H₂ detection at RT.
• To investigate the role of palladium (Pd) catalysts in enhancing H₂ sensing performance.
• To explore the fundamental mechanism of catalyst sensitization in selenide-based sensors.

Main Methods:

• Fabrication of In₂Se₃ films using chemical vapor deposition (CVD) and atomic layer deposition (ALD).
• Sensitization of In₂Se₃ films with palladium (Pd) catalysts.
• Characterization of sensor response to H₂ and NO₂ at RT.
• Density functional theory (DFT) calculations to elucidate the sensing mechanism.

Main Results:

• Pristine In₂Se₃ films showed high NO₂ response but were insensitive to H₂.
• Pd-In₂Se₃ sensors demonstrated high sensitivity to sub-parts-per-million (ppm) levels of H₂ at RT.
• The sensitized sensors exhibited rapid response and recovery times for H₂ detection.
• DFT calculations confirmed the critical role of Pd nanoparticles in the H₂ sensing reactions.

Conclusions:

• Palladium sensitization significantly enhances the H₂ detection capabilities of In₂Se₃ films at room temperature.
• This work presents a promising approach for developing high-performance selenide-based sensors for low-concentration H₂ monitoring.
• The study provides fundamental insights into the catalytic sensitization mechanism crucial for advanced sensor design.