▎ 摘　　要

Photocatalytic composites with high activity have great potential in the purification of dye wastewater. Herein, reduced graphene oxide (rGO) modified TiO2 nanobelts (TG) hybrids with desirable nanostructures were successfully prepared by regulating the addition amount of Li+ via a facile solvothermal process. The results of characterizations indicate that the introduction of two-dimensional (2D) graphene sheet restricts the agglomeration of 1D nanostructures and drives the freestanding growth of TiO2 nanobelts. Meanwhile, the addition of Li not only promotes the formation of TiO2 nanobelts but also affects the distribution of TiO2 nanobelts on the surface of rGO. The TG-2 synthesized by adding an appropriate amount of Li+ exhibits the best photodegradation activity of these samples, even better than commercial P25. The excellent photocatalytic performance of TG-2 is mainly attributed to the effective separation of charge carriers promoted by the synergistic effect between uniform TiO2 nanobelts and rGO. The trapping experiments of reactive species show that center dot OH may be the dominant species in the photodegradation process. Moreover, the activity of the catalyst does not decrease after five cycles.