Effect of PMMA on the surface of exfoliated MoS2 nanosheets and their highly enhanced ammonia gas sensing properties at room temperature

Highly sensitive ammonia (NH3) gas sensors were fabricated through polymethyl-methacrylate (PMMA) assisted exfoliation of molybdenum disulfide (MoS2) based multilayered nanosheets. The PMMA-MoS2 nanocomposites were successfully prepared by facile ultra-sonication technique. The physical-chemical properties of PMMA assisted MoS2 nanocomposites were evaluated by various analytical methods. High resolution Transmission Electron Microscopy and AFM results were revealed the uniform and thin surface coating of PMMA on the MoS2 sheets. Most importantly, obtained PMMA-MoS2 nanocomposites were dropped on SiO2/Si substrates, subsequently fabricated lateral integrated Pt electrodes to measure the gas sensing properties. Remarkable sensing properties obtained for PMMA-MoS2 nanocomposite-based sensor with an excellent sensitivity of (54%), which is significantly higher than that of bulk MoS2 (15.2%). Moreover, the fabricated PMMA-MoS2 nanocomposites based gas sensor possesses excellent selectivity to H2, C3H6O, and CO2. The observed results exhibit that the exfoliation of MoS2 with PMMA using ultra sonication techniques are promising for enhanced NH3 gas monitoring. Compared to the pure MoS2, the adsorption ability of PMMA-MoS2 surface induces the oxygen functional groups strongly affect the sensing properties. The superior gas sensing properties of this present surface modified PMMA-MoS2 hybrid sensors are promising and sustainable compared with the existing MoS2 based NH3 sensors. © 2020 Elsevier B.V.