▎ 摘　　要

This work carefully investigated the hydrothermal reduction of graphene oxide (GO) sheets. To evaluate the reduced extent, the as-prepared GO and RGO sheets in different conditions were measured by FT-IR, UV-Vis, Raman spectra and TEM morphologies. It revealed that the hydrothermal reduction of GO sheets was undergone four steps and the optimal condition was treated at 180 degrees C for 24 h. These RGO sheets exhibited the expectant morphologies and maintained the original sizes. (C) 2016 Elsevier B.V. All rights reserved.