Fabrication, characterization and enhanced sensing performance of graphene-TiO_2 gas sensor device

摘要

Graphene-TiO_2 nanocomposite layers (G-TiO_2-NCLs) were prepared using sol-gel method along with spin coating deposition and applied for detection of CO_2 gas. The physicochemical properties of G-TiO_2-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 (FT-IR). The gas sensing properties of the prepared G-TiO_2-NCLs was successfully demonstrated by detection of CO_2 gas at different operating temperatures and gas concentrations. Both pristine TiO_2 and G-TiO_2-NCLs sensors showed a faster response at operating temperature of 200 ℃. It was found that G-TiO_2 gas sensors show higher response toward sensing CO_2 gas compared with pristine TiO_2 sensors at optimum temperature. The enhancement in the gas sensing performance of G-TiO_2-NCLs can be ascribed to the introducing of graphene into the TiO_2 matrix. The response of G-TiO_2-NCLs gas sensors was maximum (1.34) when 0.001 g graphene was incorporated into the TiO_2 matrix at 200 ℃ as an optimum operating temperature.