Graphene concentration effect on the structural and morphological properties of ZnO/G nanocomposites.

The research focusing on the role of graphene in ZnO/G nanocomposites, particularly in relation to enhancing gas sensing capabilities, has garnered significant attention. This study utilized a homemade spray pyrolysis technique alongside homemade graphene to synthesize ZnO/G nanocomposites on a quartz crystal microbalance for detecting formamide. Various concentrations of graphene (0.23, 1.13, and 2.23wt%) were systematically investigated. Morphological assessments indicated that the concentration of graphene affected the formation of graphene nanoflakes and ZnO nanorods within the thin films, leading to increased sensor roughness, which in turn enhances the number of active sites and sensitivity to formamide. Furthermore, ATR spectroscopy confirmed graphene incorporation. The sensor demonstrated hydrophilic surface characteristics, attributed to interactions in the ZnO/G matrix that elevate overall surface energy. The ZnO/G sensor achieved a detection limit of 0.29 ppm, with response and recovery times of 145 s and 35 s. It also exhibited a strong linear response (R²= 0.97215) at room temperature, showcasing its capabilities for precise formamide detection and potential for environmental monitoring applications