Highly sensitive two-dimensional MoS(2) gas sensor decorated with Pt nanoparticles

A two-dimensional molybdenum disulfide (MoS(2))-based gas sensor was decorated with Pt nanoparticles (NPs) for high sensitivity and low limit of detection (LOD) for specific gases (NH(3) and H(2)S). The two-dimensional MoS(2) film was grown at 400°C using metal organic gas vapour deposition. To fabricate the MoS(2) gas sensor, an interdigitated Au/Ti electrode was deposited using the electron beam (e-beam) evaporation method with a stencil mask. The MoS(2) gas sensor without metal decoration sensitively detects NH(3) and H(2)S gas down to 2.5 and 30 ppm, respectively, at room temperature (RT). However, for improved detection of NH(3) and H(2)S gas, we investigated the functionalization strategy using metal decoration. Pt NP decoration modulated the electronic properties of MoS(2), significantly improving the sensitivity of NH(3) and H(2)S gas by 5.58× and 4.25×, respectively, compared with the undecorated MoS(2) gas sensor under concentrations of 70 ppm. Furthermore, the Pt NP-decorated MoS(2) sensor had lower LODs for NH(3) and H(2)S gas of 130 ppb and 5 ppm, respectively, at RT.