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The increasing demand of hydrogen (H2) as an alternative clean fuel emboldened the parallel development of extremely sensitive room-temperature H2 sensors for safety purposes. Molybdenum disulfide (MoS2) is an intriguing material, exhibiting a high chemical sensing ability. However, usage of MoS2 in H2 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 H2 sensor based on Pt nanoparticle-functionalized vertically aligned large-area MoS2 flakes. The fabricated Pt@MoS2 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 MoS2–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 H2 for Pt@MoS2 leading to improved and selective H2 response. This study offers Pt nanoparticle-sensitized MoS2 as a potential candidate for the development of low-power and room-temperature H2 sensors for near future hydrogen vehicles and related technologies.

Recently, Molybdenum disulfide (MoS2) has attracted great attention due to its unique characteristics and potential applications in various fields. The advancements in the field have substantially improved at the laboratory scale however, a synthesis approach that produces large area growth of MoS2 on a wafer scale is the key requirement for the realization of commercial two-dimensional technology. Herein, we report tunable MoS2 growth with varied morphologies via RF sputtering by controlling growth parameters. The controlled growth from in-plane to vertically-aligned MoS2 flakes has been achieved on a variety of substrates (Si, Si/SiO2, sapphire, quartz, and carbon fiber). Moreover, the growth of vertically-aligned MoS2 is highly reproducible and is fabricated on a wafer scale. The flakes synthesized on the wafer show high uniformity, which is corroborated by the spatial mapping using Raman over the entire 2-inch Si/SiO2 wafer. The detailed morphological, structural, and spectroscopic analysis reveals the transition from in-plane MoS2 to vertically-aligned MoS2 flakes. This work presents a facile approach to directly synthesize layered materials by sputtering technique on wafer scale. This paves the way for designing mass production of high-quality 2D materials, which will advance their practical applications by integration into device architectures in various fields.

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