In this study, we successfully synthesized ZnO quantum dots decorated on graphene oxide (GO) and graphene nanoplatelets (GNP) using a simple hydrothermal method. The synthesized ZnO/GO and ZnO/GNP nanocomposites were thoroughly characterized using various techniques, including X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), Raman and photoluminescence spectroscopies, Transmission electron microscopy (TEM), and Brunauer–Emmett–Teller analysis (BET). We further evaluated the gas sensing capabilities of the synthesized samples. Excitingly, our results demonstrated that the ZnO/GNP sensor exhibited significantly enhanced gas sensing performance for ethylene glycol compared to both the ZnO/GO and pure ZnO sensors. Specifically, at 280 ◦C, the ZnO/GNP nanocomposite sensor displayed impressive responses of approximately 51 and 183 towards 50 ppm and 200 ppm ethylene glycol, respectively. Moreover, the ZnO/GNP sensor exhibited exceptional selectivity in detecting ethylene glycol. These findings suggest that ZnO quantum dots decorated on commercial graphene nanoplatelets could be a promising candidate for highly sensitive ethylene glycol gas sensors.
