▎ 摘　　要

Graphene oxide (GO) is the key for the large-scale production of graphene by chemical oxidation-thermal reduction route. However, the current synthesis methods of GO involve concentrated sulfuric acid and potassium permanganate, which poses a risk of explosion and potential environmental pollution. Furthermore, a large number of oxygen-containing functional groups cause GO sheets to swell, posing a major challenge to the purification process. In this paper, a one-pot hydrothermal method is developed to synthesize pre-reduced graphene oxide (PRGO). The precursor is then employed to produce reduced graphene oxide (RGO) by further hightemperature thermal reduction. It not only avoids the complex temperature control and dilution operations during the oxidation and exfoliation processes but also enables the recycling of sulfuric acid. The synthesized weakly hydrophilic PRGO is highly conducive to achieve rapid filtration, which simplifies the purification process. The obtained reduced graphene oxide exhibits high rate capability and stable long cycling performance as the anode of lithium-ion batteries. This simple, safe and green synthesis route paves the way to large-scale preparation of graphene and its application for Li-ion storage.