Size-Tunable Flowerlike MoS₂ Nanospheres Combined with Laser-Induced Graphene Electrodes for NO₂ Sensing

Flexible gas sensors capable of working at room temperature are in great demand for the Internet-of-things (IoT) revolution. Although molybdenum disulfide (MoS₂) is a promising material for NO₂ gas sensing, the influence of morphology on sensing performance is not well understood. Existing gas sensors using conventional electrodes involve complex fabrication processes, resulting in high cost, thus severely limiting their ubiquitous application. In this paper, the design, fabrication, and characterization of MoS₂ gas sensors utilizing laser-induced graphene (LIG) electrodes are presented. Morphology evolution of MoS₂ nanostructures and the resulting gas sensing performance trade-offs are discussed. The flexibility and mechanical robustness of the sensors utilizing LIG electrodes have also been confirmed to be excellent. Overall, high performance in gas sensing combined with low susceptibility to mechanical damage enables the sensor to serve a variety of wearable sensory applications.