Optical and gas sensing properties of TiO2/RGO for methanol, ethanol and acetone vapors

Abstract

• Preparation of TiO 2 /RGO nanocomposite by annealing method at 180 °C. • Employing TiO 2 /RGO nanocomposite toward sensing methanol, ethanol and acetone vapors with different ppm. • Observation an excellent response for ethanol detection even in low gas volume. Reduced graphene oxide and metal oxides derivatives are introduced as relatively benign materials for improving gas sensors' performance as exemplified by the synthesis of TiO 2 /GO nanocomposite via ultrasonication, and then the assembly of RGO adorning TiO 2 nanoparticles (NPs) (TiO 2 /RGO) is accomplished using the thermal annealing method. The characterization of the as-fabricated sample indicated that irregular shaped TiO 2 NPs with size of 26 nm covered the RGO nanosheets. The optical band gap measurement indicated the values of 3.19, 2.1 and 2.5 eV for TiO 2 , GO and TiO 2 /RGO samples, respectively. The ensued nanocomposites are then deployed for the gas sensing response of three common organic vapors of ethanol, methanol, and acetone with concentrations of 20, 40, 60, 80, 100 ppm, at ambient temperature. The TiO 2 /RGO sensor relatively exhibited an excellent response (3–4 times) for ethanol detection. These results indicated that the application of TiO 2 /RGO can help assist in the evolvement of portable gas sensing devices endowed with the capability to detect common place organic vapors.