Design of a Metal-Oxide Solid Solution for Sub-ppm H₂ Detection

Area of Science:

• Materials Science
• Chemical Engineering
• Sensor Technology

Background:

• Hydrogen (H2) is vital for industry and renewable energy storage but poses safety risks due to its high explosivity.
• Reliable detection of H2 at sub-parts per million (ppm) concentrations is essential for safety in industrial applications, storage, and transportation.
• Chemoresistive gas sensors offer a promising, low-cost solution for H2 monitoring, but require further development for enhanced sensitivity and reliability.

Purpose of the Study:

• To design and develop a novel sensing film for high-sensitivity hydrogen (H2) detection.
• To investigate the effect of niobium (Nb) doping on the sensing properties of tin-titanium (Sn-Ti) oxide solid solutions.
• To achieve reliable H2 detection at sub-ppm concentrations for improved safety and monitoring.

Main Methods:

• Synthesis of Sn-Ti oxide solid solutions with varying Nb concentrations (1.5-5 atom %) using the sol-gel technique.
• Thermal treatment of synthesized powders at 650 °C and 850 °C.
• Fabrication and testing of chemoresistive gas sensors based on the prepared solid solutions.

Main Results:

• The sensor based on the Sn-Ti oxide solid solution calcined at 650 °C with the lowest Nb content demonstrated exceptionally high sensitivity to H2.
• This optimized sensor design enables H2 detection at the parts per billion (ppb) level.
• Compared to pure SnO2 and undoped (Sn,Ti)O2, the response to 50 ppm H2 was increased sixfold and twofold, respectively.

Conclusions:

• Niobium doping effectively enhances the H2 sensing performance of Sn-Ti oxide solid solutions.
• The developed sensing film shows significant potential for highly sensitive and reliable H2 detection at sub-ppm concentrations.
• This advancement contributes to improved safety protocols in industries utilizing hydrogen and in renewable energy storage systems.