Graphene strongly wrapped TiO₂ for high-reactive photocatalyst: a new sight for significant application of graphene.

A new idea was employed to simultaneously reduce graphene oxide (GO) and wrap it on the surface of high-reactive anatase TiO2 for fabricating novel TiO2-graphene (GP) hybrid materials. The process was based on the surface negatively charged property of GO. With the introduction of strong chemical interaction between TiO2 and GP, the GP wrapped TiO2 gives a strong red-shift of the light absorption edge and a further narrowed bandgap compared to that of GP randomly supported TiO2. This structure can also significantly enhance the separation efficiency of photogenerated electrons and holes. Furthermore, in contrast to the normal anatase TiO2, as-prepared TiO2 is dominated with the high-reactive {001} facet. The superiority of the formed "core-shell" structure is confirmed by photocatalytic degradation of methylene blue (MB) under the xenon lamp and visible light irradiation. New photocatalytic mechanisms are also proposed based on the obtained results. This work may open a new doorway for new significant application of GP to prepare more GP-based high-reactive photocatalysts for environmental protection.