▎ 摘　　要

Achieving high photocatalytic activity of titania-graphene composites calls for well-controlled titania size and efficient charge transfer interfaces. However, it is rather difficult because of easy restacking of graphene sheets and random nucleation and growth of titania nanoparticles in solution. Here, we reported a facile way to control the TiO2 sizes and interfaces by localizing the nucleation and growth of titania on graphene sheets, which prohibits both restacking of graphene and random growth of TiO2. As a result, a composite with controllably less than 10-nm-sized TiO2 nanoparticles evenly distributed on thin graphene sheets was achieved. Thanks to the small size of titania and efficient charge transfer interfaces, the TiO2/graphene composite exhibits a significant enhancement of photocatalytic H-2 evolution activity, reaching 1.35 mmol g(-1) h(-1). Furthermore, the composite also shows high photocatalytic activity on dye degradation under visible light illumination.