Graphene-TiO2 nanocomposite layers (G-TiO2- NCLs) were prepared using sol–gel method along with spin coating deposition and applied for detection of CO2 gas. The physicochemical properties of G-TiO2-NCLs gas sensors were determined by X-Ray diffraction (XRD), ultra-violet visible spectroscopy (UV–Vis), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Fourier transform infrared-spectroscopy (FTIR). The gas sensing properties of the prepared G-TiO2- NCLs was successfully demonstrated by detection of CO2 gas at different operating temperatures and gas concentrations. Both pristine TiO2 and G-TiO2-NCLs sensors showed a faster response at operating temperature of 200 °C. It was found that G-TiO2 gas sensors show higher response toward sensing CO2 gas compared with pristine TiO2 sensors at optimum temperature. The enhancement in the gas sensing performance of G-TiO2-NCLs can be ascribed to the introducing of graphene into the TiO2 matrix. The response of G-TiO2-NCLs gas sensors was maximum (1.34) when 0.001 g graphene was incorporated into the TiO2 matrix at 200 °C as an optimum operating temperature.
