Synthesis and photocatalytic performance of reduced graphene oxide–TiO 2 nanocomposites for orange II degradation under UV light irradiation

Abstract

To enhance the photocatalytic activity of TiO₂, reduced graphene oxide–TiO₂ (RGO–TiO₂) composites with sandwich-like structure were synthesized using a simple solvothermal method. The morphology, crystalline information, and structural property of the photocatalyst were characterized by field emission scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and Fourier transmission infrared spectroscopy. The photocatalytic performances of the RGO–TiO₂ composites were evaluated by the degradation of orange II (AO7) in water under UV light irradiation. The results showed that the RGO–TiO₂ composites exhibited much higher photocatalytic activity than TiO₂ and that the removal efficiency of AO7 could reach above 95% only after 20 min of UV light irradiation under the optimum condition. The improved photocatalytic activity might be attributed to the improved charge transfer and significant separation of the photoinduced electrons and holes in the presence of a two-dimensional graphene network. The results of recycling experiments show that RGO–TiO₂ composites have a high photostability, which is expected in the practical application. Radical trapping experiments indicated that ·OH plays a crucial role in the process of AO7 degradation.

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