Synthesis of transparent few layer graphene films using a dual flame approach for the ammonia gas sensor

Abstract

With regard to graphene preparation, dual flame synthesis method has significant advantages from the up-scaling perspective in terms of cost-effectiveness and fast processing compared to other methods. In this study, a few layer graphene (FLG) films were prepared on quartz in only 1 min using a dual flame approach at different temperatures (600, 700 and 800 °C). The structural, morphological, and optical features of FLG films as well as its gas sensing ability of ammonia gas (NH₃) were reported. Raman analyses prove the crystallinity of the prepared FLG with two characteristic bands namely I_D and I_G. X-ay diffraction (XRD) results present the FLG films have a hexagonal phase with a distinguished orientation along the direction (002). Optical spectra demonstrate the transmittance reduces and FLG layers increase as temperature increases. Transmission electron microscope (TEM) images display the FLG films have high quality with smooth surfaces and flat structures. The best data are obtained in graphene films, where few layers, high crystallinity, and highest sensitivity toward NH₃ gas. The FLG-based sensors revealed high sensitivity and selectivity to NH₃ over dimethylformamide, toluene, acetone, and carbon dioxide (CO₂) at room temperature. These results verified that the preparation approach designed in this work yielded transparent FLG films with acceptable quality and functional performance.

Keywords:

• Graphene
• flame synthesis method
• X-ray-diffraction
• TEM
• gas sensor

Disclosure statement

Authors declare there is no conflict of interest.