Low-Temperature Hydrogen Sensor: Enhanced Performance Enabled through Photoactive Pd-Decorated TiO₂ Colloidal...

Area of Science:

• Materials Science
• Chemical Engineering
• Sensor Technology

Background:

• Hydrogen gas (H2) sensing is critical for industrial, food, and medical applications, including noninvasive disease diagnosis.
• Achieving high sensitivity and low limit of detection (LoD) for H2 remains a significant challenge.

Purpose of the Study:

• To develop a highly sensitive H2 gas sensor with a low LoD.
• To explore the performance of Pd-decorated TiO2 long-range ordered crystals in light-assisted amperometric sensors.

Main Methods:

• Fabrication of a light-assisted amperometric gas sensor with a sensitive layer of Pd-decorated TiO2 long-range ordered crystals.
• Testing sensor performance under varying conditions, including the presence of light and different bias voltages.
• Evaluating sensor selectivity against common coexisting gases.

Main Results:

• The developed sensor achieved H2 detection down to 50 ppm.
• Under optimal conditions (9 V bias, 33 °C, with light), the LoD was significantly reduced to 3.5 ppm.
• The sensor demonstrated high signal-to-noise ratio in the presence of light.

Conclusions:

• The novel sensor design offers excellent H2 sensing performance, suitable for low-level gas detection.
• High selectivity (>93%) towards H2 over other gases makes it robust for real-world applications.
• The sensor's capabilities are promising for breath analyzers and other medical diagnostic tools.