Highly Sensitive Platinum-Decorated Tungsten Oxide for Ultra-Low-Concentration Hydrogen Detection

초록

The global transition towards a hydrogen-based economy has increased the need for highly sensitive hydrogen gas sensors capable of detecting ultra-low concentrations. Although conventional hydrogen sensors have been widely studied and applied, they face fun-damental limitations in terms of sensitivity, selectivity, and power consumption at low concentrations. Here, we report a high-per-formance hydrogen sensor based on platinum-decorated tungsten oxide (WO<inf>3</inf>/Pt) fabricated using MEMS technology. The sensor was systematically constructed through the sequential processes of thermal oxidation, LPCVD, electrode patterning, and membrane for-mation. The WO<inf>3</inf>/Pt composite, synthesized via a modified wet impregnation method and thoroughly characterized via XRD, demon-strated a uniform platinum distribution on the WO<inf>3</inf> surface. The fabricated sensor exhibited exceptional sensitivity across a hydrogen concentration range of 100–500 ppm with enhanced concentration resolution and reproducibility. Under optimal operating conditions at 300°C, the sensor achieved rapid response/recovery kinetics while maintaining a low power consumption of 42.1 mW. The enhanced sensing performance is attributed to the synergistic effects between WO<inf>3</inf> and the Pt catalyst, specifically the spillover effect and efficient modulation of the depletion layer at the Pt-WO<inf>3</inf> interface. © 2024, Korean Sensors Society. All rights reserved.

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