Synthesis of graphene based on the improved solvothermal reduction

Graphene has attracted much attention because of its unusual electron transport properties and other distinctive characteristics. Various methods have been developed to produce graphene, such as mechanical [1], physical [2], and chemical methods [3, 4], in which chemical method can produce graphene in large scale. Currently, many research groups prefer to use graphite oxide (GO) as starting material for chemical production of graphene. Three major reduction methods are used to reduce GO: thermal reduction, reduction of reducing agent, and solvothermal reduction. Although chemical reduction of GO can produce graphene, the products contain significant numbers of oxygen-containing functional groups generated in oxidation and irreversible lattice defects. Solvothermal reduction is a facile and low-cost method for producing graphene. Many groups have studied the solvothermal reduction for producing graphene. However, the reduced GO still have many residual oxygen-containing functional groups [5, 6]. In order to decrease the contents of oxygen, more effective reduction methods are urgently needed.