A facile one-step solvothermal synthesis of graphene/rod-shaped TiO2 nanocomposite and its improved photocatalytic activity

Graphene sheets were obtained through solvothermal reduction of colloidal dispersion of graphene oxide in benzyl alcohol. The graphene/rod-shaped TiO2 nanocomposite was synthesized by this novel and facile solvothermal method. During the solvothermal reaction, both the reduction of graphene oxide and the growth of rod-shaped TiO2 nanocrystals as well as its deposition on graphene occur simultaneously. The photocatalytic activity of graphene/rod-shaped TiO2 and graphene/spherical TiO2 nanocomposites was compared. In the photocatalytic degradation of methyl orange (MO), the graphene/rod-shaped TiO2 nanocomposite with the optimized graphene content of 0.48 wt% shows good stability and exhibits a significant enhancement of photocatalytic activity compared to the bare commercial TiO2 (P25) and graphene/spherical TiO2 nanocomposite with the same graphene content. Photocurrent experiments were performed, which demonstrate that the photocurrent of the graphene/rod-shaped TiO2 nanocomposite electrode is about 1.2 times as high as that of the graphene/spherical TiO2 nanocomposite electrode. The photocatalytic mechanism of graphene/rod-shaped TiO2 nanocomposite was also discussed on the basis of the experimental results. This work is anticipated to open a possibility in the integration of graphene and TiO2 with various morphologies for obtaining high-performance photocatalysts in addressing environmental protection issues.