Synthesis and characterization of graphene oxide for photonic applications

Graphene oxide (GO) was obtained by using Tour method. Reduction of obtain GO (rGO) was carried with Vitamin C (VitC), and structural, morphological and electrical results obtained were compared with hydrazine reduced samples. X-ray photoelectron spectrometry, X-ray diffraction spectrometry, Raman spectrometry, UltraViolet-visible spectrophotometry, Fourier infrared spectroscopy, thermal gravimetric analysis, atomic force microscope and surface resistivity measurement systems were used during characterization. For the samples which were prepared with the use of VitC under basic and neutral reaction conditions, the highest carbon:oxygen (C:O ) ratio was 6.02 and 5.37, respectively, and for the latter, the surface resistivity of the film prepared by dropping-drying is 0.25 Mohm/sq. These values were 8.35 ve 0.71 Mohm/sq, respectively for the hydrazine medium. The reduction of GO by hydrazine on the film surface resulted in transmittance loss and the surface resistivity of this film was 337 ohm/sq. Independent from the reduction agent, dispersion stability of rGO samples was very low. Therefore, GO samples were modified by primary, secondary and alcohol amine derivatives (mGO) and C:O ratio of 7.56 was achieved. With the increase in alkyl chain length of the reactant amine, the dispersion stability of mGOs in polar aprotic solvents was increased while a decrease was obtained in polar protic solvents. Composite films of the synthesized rGO and mGO derivatives with poly(3,4-ethylenedioxythiophene)-polystyrene sulfonate were prepared. The surface resistivity values of these composites were in the order of Mohm/sq and optical transmittance of > 90% was obtained in all of the films.