Liquid Shear Exfoliation of MoS(2): Preparation, Characterization, and NO(2)-Sensing Properties

2D materials possess great potential to serve as gas-sensing materials due to their large, specific surface areas and strong surface activities. Among this family, transition metal chalcogenide materials exhibit different properties and are promising candidates for a wide range of applications, including sensors, photodetectors, energy conversion, and energy storage. Herein, a high-shear mixing method has been used to produce multilayered MoS(2) nanosheet dispersions. MoS(2) thin films were manufactured by vacuum-assisted filtration. The structural morphology of MoS(2) was studied using ς-potential, UV–visible, scanning electron microscopy (SEM), atomic force microscopy (AFM), energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), X-ray diffraction (XRD), and Raman spectroscopy (RS). The spectroscopic and microscopic analyses confirm the formation of a high-crystalline MoS(2) thin film with good inter-sheet connectivity and relative thickness uniformity. The thickness of the MoS(2) layer is measured to be approximately 250 nm, with a nanosheet size of 120 nm ± 40 nm and a number of layers between 6 and 9 layers. Moreover, the electrical characteristics clearly showed that the MoS(2) thin film exhibits good conductivity and a linear I–V curve response, indicating good ohmic contact between the MoS(2) film and the electrodes. As an example of applicability, we fabricated chemiresistive sensor devices with a MoS(2) film as a sensing layer. The performance of the MoS(2)-chemiresistive sensor for NO(2) was assessed by being exposed to different concentrations of NO(2) (1 ppm to 10 ppm). This sensor shows a sensibility to low concentrations of 1 ppm, with a response time of 114 s and a recovery time of 420 s. The effect of thin-film thickness and operating temperatures on sensor response was studied. The results show that thinner film exhibits a higher response to NO(2); the response decreases as the working temperature increases.