UV-activated, high-temperature hydrogen sensing using a single Pd/SiC@C core-shell nanowire: Synergistic enhancement via plasmonic resonance and confinement effect

Abstract

To address the high-temperature degradation of conventional Pd-based hydrogen sensors, this study proposes a Pd/SiC@C core-shell nanowire heterostructure. Under UV irradiation, the localized surface plasmon resonance effect in Pd nanoparticles significantly enhances hydrogen adsorption and diffusion. At 300 °C, the sensor achieves a response of 27% to 20 ppm H₂, with response and recovery times of 3.5 s and 6.2 s, respectively. It maintains high sensitivity across a wide operating temperature range (50-300 °C) and H₂ concentration range (20-200 ppm). Notably, after 30 consecutive days of operation at 300 °C, the device exhibits negligible performance degradation. First-principles calculations confirm strong H₂ adsorption and significant interfacial charge transfer at the Pd(111)/SiC(111) interface, supporting the proposed electronic sensitization mechanism. This work establishes a robust design strategy for high-temperature, high-performance hydrogen sensors.