The photocatalytic activity of TiO2 is limited by the aggregation of nanoparticles and the fast electron–hole pair recombination. Graphene sheets, with high specific surface area and unique electronic properties, can be used as a good support for TiO2 to enhance the photocatalytic activity. Herein, we prepared graphene–TiO2 (G–TiO2) composites through a one-pot solvothermal reaction by using graphite oxide (GO) and tetrabutyl titanate as starting materials. TiO2 particles with anatase phase and a narrow size distribution were dispersed on the surface of graphene sheets uniformly. The fluorescence quenching confirmed that graphene acted as an electron-acceptor material to effectively hinder the electron–hole pair recombination of TiO2. The product prepared with 30 mg of GO and 8 h of reaction time exhibited excellent photocatalysis to methylene blue (MB) degradation under irradiation of simulated sunlight. Such intriguing photocatalyst may find significant applications in various fields.