Pt Nanoparticles on Vertically Aligned Large-Area MoS₂Flakes for Selective H₂Sensing at Room Temperature

The increasing demand of hydrogen (H 2 ) as an alternative clean fuel emboldened the parallel development of extremely sensitive room-temperature H 2 sensors for safety purposes. Molybdenum disulfide (MoS 2 ) is an intriguing material, exhibiting a high chemical sensing ability. However, usage of MoS 2 in H 2 sensors has been limited and usually suffers from low sensitivity and selectivity, especially at room temperature. In this work, we report a highly sensitive and selective H 2 sensor based on Pt nanoparticle-functionalized vertically aligned large-area MoS 2 flakes. The fabricated Pt@MoS 2 sensor exhibits a high sensitivity value of 23%, excellent reproducibility, fast response, and complete recovery at room temperature. The superior response of the sensor is attributed to the spillover effect and adsorption sites distributed on the Pt surface and the MoS 2 –Pt interface. The influence of operating temperature on the sensing performance is also investigated. Density functional theory calculations validate our experimental results and demonstrate higher adsorption of H 2 for Pt@MoS 2 leading to improved and selective H 2 response. This study offers Pt nanoparticle-sensitized MoS 2 as a potential candidate for the development of low-power and room-temperature H 2 sensors for near future hydrogen vehicles and related technologies.