Pd-Sensitized In ₂ Se ₃ Films Boost Low-Concentration H ₂ Detection

Hydrogen (H₂) detection at room temperature (RT) remains a challenge for conventional chemiresistive sensors. Herein, we report the synthesis and integration of Pd-sensitized In₂Se₃ (Pd-In₂Se₃) films for H₂ sensors by using chemical vapor deposition and atomic layer deposition. The pristine In₂Se₃ films exhibit a high response to NO₂ and are insensitive to H₂. After sensitization with Pd catalysts, the Pd-In₂Se₃ sensor becomes very sensitive to sub-ppm H₂ with fast response and recovery. To our best knowledge, this is among the limited number of studies that demonstrate the feasibility of using In₂Se₃ materials to construct sensors for low-concentration H₂ detection at RT. Density functional theory calculations reveal that the Pd nanoparticles play a crucial role in the sensing reactions. This work sheds new light on the fabrication and integration of selenide films in high-performance sensors and also contributes to the fundamental understanding of the sensitization mechanism of catalysts in sensors.