▎ 摘　　要

In this work, the dispersibility of graphene oxide (GO) nanosheets in an aqueous solution was significantly improved by applying air-water plasma using the dielectric barrier discharge (DBD) technique. The effects of different process variables such as the voltage, frequency, and the processing time of air-water plasma treatment on the oxidation degree of GO nanosheets were investigated by Fourier transform infrared (FT-IR) spectroscopy and other characterization methods. High-resolution transmission electron microscopy (HR-TEM), energydispersive X-ray spectroscopy (EDS), Fourier transform infrared (FT-IR), ultraviolet-visible (UV-vis) spectroscopy, X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and X-ray diffraction (XRD) were employed to characterize the modified and unmodified GO nanoparticles. Finally, the stability of functionalized and nonfunctionalized GO nanosheets in aqueous media was investigated by UV-vis spectroscopy. According to the results, the plasma-treated GO nanosheets contained the maximum number of bonded carbonyl/carboxyl groups among the studied samples at a frequency (f) of 6 kHz, a voltage (V) of 8 kV, and a processing time (t) of 5 min.