Atomic layer deposited Pt nanoparticles on functionalized MoS2 as highly sensitive H-2 sensor

Hydrogen gas (H-2) 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 H-2 sensing material. However, pristine MoS2 exhibits low sensitivity to nonpolar H-2. 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 H-2 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 H-2 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.