Reduced graphene oxide coated optical fiber for methanol and ethanol vapor detection at room temperature

Abstract

ABSTRACT Successful isolation of single layer of graphene from grap hite by mechanical exfoliatio n method, attracted a great attention due to its unique structural, optical, mechanical and electronic properties. Th is makes the graphene as a promising material in many possible applications such as energy-storage, sensing, electronic, optical devices and polymer composite materials. High quality of reduced graphene oxide (rGO) material was prepared by chemical reduction method at 100°C. The stru ctural and optical properties of the rGO sheets were characterized by FT-IR, micro Raman, powder XRD and UV-vis-NIR techniques. FT-IR reveals the absence of oxygen functional groups on rGO due to the reduction process. Powder XRD shows the broad peak at 2T=24.3° corresponding to interlayer spacing 3.66A which is smaller than the graphene oxide (GO). UV-vis-NIR of rGO displays the absorption peak at 271 nm indicates the reduction of GO and the restoration of C=C bonds in the rGO sheets. The cladding removed and rGO coated poly-methyl me thacrylate (PMMA) optical fiber is used for methanol and ethanol vapors detection in the concentration ranging from 0 to 500 ppm at room temperature. The spectral characteristics along with output intensity modulation of cladding removed and rGO coated fiber optic sensor reveal the potential of methanol and ethanol vapor sensing properties. Key words: reduced graphene oxide, fiber optic sensor, ethanol and methanol vapor sensor, PMMA fiber