Effect of synthesis technique on the formation of surface-active reduced graphene oxide (rGO) wrapped SnS₂ nanosphere modified electrode: A comparative study on CO sensing behaviours

Transition metal dichalcogenides based chemiresistors frequently encounter challenges, such as inadequate performance at room temperature and limited sensitivity for detecting low gas concentrations. In this study, we successfully developed a carbon monoxide (CO) low-cost OHP patterned sensor electrode using reduced graphene oxide rGO-SnS₂ nanocomposite thin films that operate effectively at ambient temperature (29 ± 2 °C) and exhibit a robust sensor response. The sensor was fabricated using simple physical and chemical methods. We characterized the structural and surface characteristics of the inexpensive sensor electrode with an OHP pattern sensor electrode, which include pristine rGO, SnS₂, and their nanocomposites, using structural and surface morphological techniques such as X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and high-resolution transmission electron microscopy (HR-TEM) respectively. The surface chemical state of the deposited layer has been systematically analyzed through X-ray photoelectron spectroscopy (XPS). The CO sensing performance of these chemiresistive sensors was assessed using I/V measurements. The nanocomposite thin films demonstrated the sensor demonstrated quick reaction and recovery times of 11 and 10 s, respectively, with a maximum response of 90 % and a detection limit of 2.91 ppm for CO gas., respectively for CO gas detection.