High-quality graphene flakes have been exfoliated directly from graphite by solvothermal treatment. By introducing the oil/water interface, graphene can be easily and quickly separated from the graphene/NMP solution, which overcomes shortcomings of the time-consuming method of filtration. At the same time, the graphene film can be fabricated at the oil/water interface by controlling the volume of graphene/NMP solution. Furthermore, carbon nanotube/carbon nanospheres films can also be prepared successfully through the same separation method.