Sol-gel derived GO/TiO2 nanocomposites for room temperature acetone gas sensing application

The chemically synthesized pristine TiO2 and GO/TiO2 nanocomposites were employed for the fabrication of room temperature acetone gas sensors. Four samples of GO/TiO2 nanocomposites were synthesized with 1, 3, 5 and 7 wt% of graphene oxide (GO) by the Sol-gel route. The crystal structure of the synthesized samples was investigated by X-ray diffraction. Crystallite size calculated by Debye Scherer's formula was found to be decreased with the increasing concentration of GO. The surface morphology of the synthesized nanocomposites was examined under field emission scanning electron microscopy (FE-SEM). The particle size of GO/TiO2 nanocomposite with 3 wt% and pristine TiO2 was found to be 11.9 and 13.86 nm respectively from FESEM analysis. Raman spectra confirmed the presence of all fundamental bands of pristine TiO2 and GO/TiO2 nanocomposites. Raman intensity was found to be decreasing significantly with an increase in GO concentration. The presence of peaks corresponding to Ti-O-Ti, Ti-O-C and Ti-C bonds in the FTIR spectrum confirmed the synthesis of the composite. The variation in electric current with change in surroundings (air to acetone and back to air) was used to calculate various sensing parameters at 100 and 200 ppm concentrations of acetone. The percentage response of the synthesized samples was found to be increased with an increase in GO concentration as well as acetone ppm level. The GO/TiO2 nanocomposite with 7 wt% of GO has shown the highest percentage response of 18.66% at 200 ppm. The lowest response time of the 80 s was shown by the GO/TiO2 nanocomposite with 7 wt% of GO.

Automated summary

Chemically synthesized pristine TiO2 and GO/TiO2 nanocomposites were used to fabricate room temperature acetone gas sensors. The crystal structure and surface morphology of the synthesized samples were investigated and controlled by varying the concentration of GO. The GO/TiO2 nanocomposite showed good response rate and response time to acetone at a concentration of 200 ppm.