Study on efficient and green reduction of graphene oxide by a one-step hydrothermal method

Abstract

This work reports an efficient and green reduction method of graphene oxide (GO) by a one-step hydrothermal process. GO was prepared by the oxidation of graphite using a modified Hummers method. The reduced graphene oxide (rGO) were characterised and studied by means of UV-vis absorption spectra, Raman spectroscopy and transmission electron microscope (TEM) techniques. UV-vis absorption spectra revealed that GO was successfully reduced to rGO and the π-conjugated structure was restored. Raman spectroscopy suggested that rGO had a smaller average size of the in-plane sp2 domains and more sp2 domains than that of GO. Fourier transform infrared (FTIR) spectra demonstrated that most oxygen functionalities on the GO were removed after the reduction. TEM images further confirmed that there was no irreversible agglomeration of rGO layers. Furthermore, we proposed a possible mechanism for the reduction of GO with subcritical water under hydrothermal condition. This study provides a novel idea for developing environmentally friendly reduction methods of GO.