High-Performance H₂ Sensors Based on a Hydrogen Spillover-Triggered Reversible W⁶⁺/W⁵⁺ Transformation Strategy for...

Area of Science:

• Materials Science
• Nanotechnology
• Chemical Sensing

Background:

• Noble-metal catalysts are crucial for semiconductor metal oxide hydrogen sensors.
• Limited surface oxygen species hinder the redox reaction between activated hydrogen and oxygen.

Purpose of the Study:

• To develop a PtPd bimetallic nanoparticle-decorated WO3 nanosheet sensor for enhanced hydrogen detection.
• To overcome the bottleneck of limited chemisorbed oxygen species in hydrogen sensing.

Main Methods:

• Decoration of WO3 nanosheets with PtPd bimetallic nanoparticles.
• Gas-sensing measurements at 150 °C with 10 ppm H2.
• Mechanism analysis using in situ Raman spectroscopy, gasochromic experiments, and density functional theory (DFT) calculations.

Main Results:

• PtPd-WO3 exhibited a response of 298% to 10 ppm H2, significantly outperforming pristine WO3 and Pd-WO3.
• Response time was reduced to 4 s.
• Demonstrated hydrogen spillover and reversible W6+/W5+ transformation, leading to bulk-involved lattice redox processes and amplified sensing signals.

Conclusions:

• PtPd bimetallic nanoparticles effectively enhance WO3-based hydrogen sensors by facilitating hydrogen dissociation and activating the WO3 surface.
• The developed sensor enables rapid and sensitive detection of hydrogen, with potential applications in real-time monitoring systems like UAV-based pipeline monitoring.