Influence of morphology and interfacial interaction of TiO2-Graphene nanocomposites on the visible light photocatalytic performance

In most cases, different morphologies of the same composites correspond to different properties. In this paper, the TiO2/rGO heterostructure system with three morphologies was obtained by one-step hydrothermal method through regulating hydrothermal time. Compared with TiO2 nanoparticle/reduced graphene oxide (TNP/rGO) and TiO2 nanobelt/reduced graphene oxide (TNB/rGO), TiO2 nanotube/reduced graphene oxide (TNT/rGO) showed higher photocatalytic activity (78.5%, 2 ​h) toward degrading Rhodamine B and 2, 4-Dichlorophenol under visible light. The mechanism of enhancing photocatalytic activities of the TiO2/rGO system was confirmed by free radicals trapping experiment, ESR, PL and photocurrent measurement. It is revealed that the hole (h+) is the main reactive specie in TNT/rGO heterojunction and rapid transfer of photogenerated electrons is responsible for enhancing photocatalytic activity. This work not only emphasizes the important role of morphology in improving photocatalytic activity, but also provides a simple strategy to alter the morphology of TiO2.