▎ 摘　　要

Functional group free graphene materials with high electronic conductivities were prepared via solvothermal reaction of solid sulphur (S) and graphene oxide (GO) in a H2O-NMP or H2O-DMF (1 : 1 in volume ratio) solvent at 110 degrees C for 10 h. Ultraviolet-visible (UV/Vis) analysis revealed that S exhibited strong reductive ability in a boiling GO aqueous solution. Its reducing effect could be further enhanced by using NMP or DMF as a surfactant to adjust the solvent surface tension close to the surface energy of graphene. UV/Vis and X-ray photoelectron spectroscopy (XPS) results confirmed that the electronic structure of graphene had been completely restored and the oxygen contents reduced remarkably. No graphitic stacking between the reduced GO (RGO) was found. As-prepared RGO products also exhibited good dispersivities in various solvents. Moreover, it was inter-convertible between their different forms: agglomerates, simply air dried bulk solids and films and well-dispersed suspensions.