Room-Temperature acetone gas sensing properties of graphene oxide/zinc oxide nanocomposites synthesized by sol-gel method

The pristine zinc oxide (ZnO) and graphene oxide (GO)-based GO/ZnO nanocomposites were chemically prepared by low-cost and facile sol-gel route for room-temperature acetone gas sensors. Nanocomposites were synthesized according to different weight percentages (2, 4, 6 wt%) of GO. Structural analysis revealed that increasing wt% of GO does not affect the crystal structure of ZnO as the wurtzite phase was maintained in all the GO/ZnO nanocomposites. Field emission scanning electron microscope (FESEM) study shows the formation of hexagonal plate-like structure with an average thickness of 29.5 and 18.83 nm for pristine ZnO and GO/ZnO nanocomposite with 2 wt%, respectively. Raman spectroscopy confirmed all the fundamental bands of ZnO with D, G and 2D bands of GO in the GO/ZnO nanocomposites. Fourier transform infrared spectroscopy (FTIR) confirmed that C=O, Zn-O, and C-O chemical bonds were present in the samples. The photoluminescence measurements show a decrease in intensity with an increase in wt% of GO. Brunauer-Emmett-Teller (BET) measurements indicate an increase in surface area with an increase in wt% of GO. The pristine ZnO shows a maximum sensing response of 15.28% and the lowest response time of 180 s at 200 ppm of acetone. At 200 ppm concentration of acetone, the nanocomposite having 6 wt% of GO showed a maximum sensing response of 41.02% with a response time as low as 70 s. Thus, the synergistic effects of ZnO nanoparticles and GO lead to excellent sensing response of the nanocomposites.

Automated summary

Pristine zinc oxide (ZnO) and graphene oxide (GO)-based GO/ZnO nanocomposites were prepared for room temperature acetone gas sensors. Structural analysis showed that increasing wt% of GO did not affect the crystal structure of ZnO. The nanocomposites exhibited a hexagonal plate-like structure, with different thicknesses depending on the wt% of GO. Raman spectroscopy confirmed the presence of fundamental bands of ZnO and GO in the nanocomposites.