Atomic layer deposited Pt nanoparticles on functionalized MoS2 as highly sensitive H2 sensor

Abstract Hydrogen gas (H2) has garnered significant attention as an alternative clean energy source, and its sensitive detection is essential to prevent explosions due to leakage in storage systems. Molybdenum disulfide (MoS2), which exhibits a large surface area-to-volume ratio from atomically thin two-dimensional (2D) structure, has attracted attention as a suitable H2 sensing material. However, pristine MoS2 exhibits low sensitivity to nonpolar H2. This paper demonstrates a decoration method for platinum (Pt) catalysts on 2D MoS2 using atomic layer deposition (ALD) and its application to fabricate highly sensitive H2 sensors. Additionally, to induce homogeneous distribution of Pt nanoparticles on chemically inert MoS2 surfaces, oxygen plasma pretreatment is employed as the MoS2 surface functionalization method. Consequently, highly sensitive detection of H2 with the sensitivity over 400 and the lower detection limit set to 2.5 ppm, is achieved using ALD Pt-decorated MoS2, and a sensing mechanism is proposed.