▎ 摘　　要

Graphene oxide (GO) and reduced graphene oxide (RGO) are in greater demand in many research fields. As a result, the synthesis of these materials on a large scale in a costeffective manner is more concerned for numerous applications. In the present work, GO was synthesized by oxidizing natural graphite and reduced by ascorbic acid (AA), which is a green reductant. The reduced products obtained at different time periods were in detail characterized by UV-Visible spectroscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), attenuated total reflectance Fourier transform infrared (ATR-FT-IR) spectroscopy, Raman spectroscopy, thermogravimetric analysis (TGA), atomic force microscopy (AFM) and scanning electron microscopy (SEM). Results showed that the oxidation of graphite has given highly oxidized GO with a 9.30 angstrom interlayer space and about 33% of oxygen atomic percentage. Until 50 min of the reduction, both GO and RGO coexist. The reduction rate is fast within the first 30 min. In addition, the suitability of natural graphite over synthetic graphite for the synthesis of GO is shown. The findings of this work pave the way to select GO and RGO for applications of interest in a cheap, green and efficient manner. (C) 2018 Elsevier B.V. All rights reserved.